quantum computing /institute-for-quantum-computing/ en IQC Colloquium featuring Francesco Di Colandrea /institute-for-quantum-computing/events/iqc-colloquium-featuring-francesco-di-colandrea <span class="field field--name-title field--type-string field--label-hidden">IQC Colloquium featuring Francesco Di Colandrea</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/tcvmudzo" typeof="schema:Person" property="schema:name" datatype="" content="tcvmudzo" xml:lang="">Takudzwa Chipo…</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 01/30/2025 - 12:50</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-d9e5377f-2c2c-4b0a-be05-eec4dd515d1b" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/headhsots-3-2.png?itok=dXf1KcHX 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/headhsots-3-2.png?itok=IrY3-dTs 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/headhsots-3-2.png?itok=TKR7vyLV 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/headhsots-3-2.png?itok=d0FvFaXi 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/headhsots-3-2.png?itok=KCwYGb3x 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/headhsots-3-2.png?itok=klk-RZ7e 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/headhsots-3-2.png?itok=sFu1s0d_" alt="Francesco Di Colandrea" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>Large-scale quantum walks via complex polarization transformations</h2> <p>Francesco Di Colandrea | University of Naples Federico II</p> <p>Optical losses are the main barrier to photonic simulations of large-scale quantum dynamics. In fact, within the standard approach, the complexity of the setup increases with the extension of the simulated evolution in time. In the case of discrete-time quantum walks, experimental realizations have typically been limited to a few tens of steps, involving at most a hundred modes.</p> <p>By focusing on different protocols of discrete-time quantum walks, we experimentally demonstrate a photonic circuit technology that compresses multiple time steps into only three liquid-crystal metasurfaces. Exploiting spin-orbit effects, these metasurfaces enable the simultaneous activation of several hundred optical modes from a single localized input, allowing for a precise and efficient reproduction of the target dynamics. Acting as waveplates with artificially patterned optic-axis orientations, the metasurfaces implement space-dependent polarization transformations that mix circularly polarized optical modes carrying quantized units of transverse momentum.</p> <p>The performance of our circuit is validated for walker dynamics spanning both one-dimensional [1] and two-dimensional [2] lattices, up to 320 and 20 time steps, respectively. The experimental results certify that our setup can process a huge number of modes while maintaining a high level of coherence. In principle, the metasurfaces can be designed for an arbitrarily large walk extension and number of connected modes, by keeping optical losses constant. Our platform thus paves the way to the simulation of extreme quantum dynamics in the multi-photon regime.</p> <p>[1] F. Di Colandrea, A. Babazadeh, A. Dauphin, P. Massignan, L. Marrucci, F. Cardano, “Ultra-long quantum walks via spin-orbit photonics”, Optica, 10(3), 2023</p> <p>[2] M. G. Ammendola, F. Di Colandrea, L. Marrucci, F. Cardano, “Large-scale spin-orbit photonic circuits in two dimensions”, arXiv:2406.08652</p> <h3>Biography</h3> <p>Francesco Di Colandrea is a researcher at the University of Naples Federico II and a visiting scientist at the University of Ottawa. His research focuses on the manipulation of structured light for quantum simulations, particularly in the study of topological physics and open quantum systems. His work also extends to quantum communications and the application of machine-learning techniques in optical experiments.</p> <h3>Location</h3> <p>QNC 0101</p> </div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Thu, 30 Jan 2025 17:50:32 +0000 Takudzwa Chipo Valerie Mudzongo 3707 at /institute-for-quantum-computing IQC Student Summer Conference /institute-for-quantum-computing/events/iqc-student-summer-conference <span class="field field--name-title field--type-string field--label-hidden">IQC Student Summer Conference </span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/tcvmudzo" typeof="schema:Person" property="schema:name" datatype="" content="tcvmudzo" xml:lang="">Takudzwa Chipo…</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 07/03/2025 - 14:25</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div class="layout__region layout__region--first"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <p class="enlarged">On Wednesday, July 23, 2025 the Institute for Quantum Computing (IQC) will host the IQC Student Summer Conference.</p> <p>This is a student-organized event that brings together students at IQC to share their research in a friendly setting. The conference aims to foster connections across different quantum research areas and provide a supportive environment for early-career researchers. All IQC members and guests are welcome to attend.</p> <h2>Organizers</h2> <p>Alec Gow, Devin Blankespoor, Jiayue Yang, Jingwen Zhu, Maria Rosa Preciado Rivas, Mikka Stasiuk, Parinaz Rafati, Sebastian Parsons-Hall, Vyom Patel and Ziyuan Yang from the Institute for Quantum Computing (IQC).</p> <h2>Location</h2> <p>The IQC Student Summer Conference will be hosted in the Mike & Ophelia Lazaridis Quantum-Nano Centre (QNC) Room 0101.</p> </div> </div> </div> </div> </section> Thu, 03 Jul 2025 18:25:32 +0000 Takudzwa Chipo Valerie Mudzongo 3842 at /institute-for-quantum-computing IQC Student seminar featuring Einar Gabbassov /institute-for-quantum-computing/events/iqc-student-seminar-featuring-einar-gabbassov <span class="field field--name-title field--type-string field--label-hidden">IQC Student seminar featuring Einar Gabbassov</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/tcvmudzo" typeof="schema:Person" property="schema:name" datatype="" content="tcvmudzo" xml:lang="">Takudzwa Chipo…</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 06/26/2025 - 13:05</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-2858b068-7341-4f9c-bdea-6adf8190dc5e" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>Adiabatic Dynamics of Entanglement</h2> <p>Einar Gabbassov </p> <p>In the world of quantum computing, entanglement is a powerful resource. Our research investigates how entanglement behaves during a special kind of quantum process called 'adiabatic evolution,' where a quantum system slowly transforms from one state to another. We've discovered that entanglement isn't just changing randomly; instead, it's precisely 'woven' and re-woven at specific points during this evolution, almost like threads in a fabric. These crucial points are called 'avoided energy level crossings,' where the system's energy levels get very close but don't quite touch.</p> <p>This weaving process has significant implications for how fast we can run adiabatic quantum computations. We found that the more efficiently entanglement needs to be manipulated (which happens at very 'narrow' avoided crossings), the slower the quantum computer must operate to maintain accuracy. Intriguingly, the amount of entanglement that builds up during a quantum computation is directly related to how 'rugged' or complex a quantum problem's energy landscape is. This provides new insights into why some quantum problems are inherently harder than others and could offer fresh perspectives on where the 'quantum advantage' truly comes from. Our work offers new tools to precisely control and study entanglement in adiabatic quantum computation.</p> <h3>Location</h3> <p>QNC 1201</p> </div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Thu, 26 Jun 2025 17:05:15 +0000 Takudzwa Chipo Valerie Mudzongo 3840 at /institute-for-quantum-computing IQC Math and CS seminar featuring Zhaoyi Li /institute-for-quantum-computing/events/iqc-math-and-cs-seminar-featuring-zhaoyi-li <span class="field field--name-title field--type-string field--label-hidden">IQC Math and CS seminar featuring Zhaoyi Li</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/tcvmudzo" typeof="schema:Person" property="schema:name" datatype="" content="tcvmudzo" xml:lang="">Takudzwa Chipo…</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 06/19/2025 - 09:16</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-878644a5-0b0b-45f8-9c64-9bcd2b7aa246" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>Designing and Implementing Optimal Quantum Purity Amplification</h2> <p>Zhaoyi Li |  Massachusetts Institute of Technology (MIT)</p> <p>Quantum Purity Amplification (QPA) offers a new framework for mitigating noise in quantum systems. In this talk, I will present the optimal QPA protocol for general quantum states under global depolarizing noise, a problem that has remained open for two decades. We prove the optimality of the protocol and show that it achieves an exponential improvement in sample complexity compared to previous methods in the strong-noise regime. I will also describe an efficient implementation based on generalized quantum phase estimation (GQPE), and introduce SWAPNET, a shallow and sparse circuit design that makes QPA practical for near-term devices. Finally, I will share simulation results demonstrating that QPA can improve fidelity in noisy Hamiltonian evolution, suggesting its potential utility in realistic applications with limited quantum resources.</p> <h3>Location</h3> <ul><li> <p>QNC 1201</p> </li> <li> <p><a href="https://uwaterloo.zoom.us/j/94293816499?pwd=OzwoZFYxOsoLSCrbAnsaolZamZhM2O.1">Online on Zoom</a></p> <ul><li> <p>Meeting ID: 942 9381 6499</p> <p>Passcode: 539850</p> </li> </ul></li> </ul></div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Thu, 19 Jun 2025 13:16:32 +0000 Takudzwa Chipo Valerie Mudzongo 3830 at /institute-for-quantum-computing IQC seminar featuring Marek Żukowski /institute-for-quantum-computing/events/iqc-seminar-featuring-marek-zukowski <span class="field field--name-title field--type-string field--label-hidden">IQC seminar featuring Marek Żukowski</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/ngrosman" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">Naomi Grosman</span></span> <span class="field field--name-created field--type-created field--label-hidden">Tue, 06/10/2025 - 14:03</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-fbea38b6-4f34-4b09-923b-dfe609ece08b" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>Violations of Bell inequality by a single photon and weak homodyne measurements</h2> <p>Marek Żukowski | University of Gdansk</p> <p>The 1991 precursory idea of such a "Bell experiment" is criticized. First, the used "Bell inequalities" are using an additional assumption. Second, we find an exact local realistic model for the 1991 correlations. Nevertheless, we show that one can find genuine violations of local realism, if one uses on-off homodyne measurements, as suggested by Hardy. We search for optimal version of such experiment, and its modifications, as well as quantum informational applications of the correlations which genuinely violate local realism.</p> <h3>Location</h3> <p>QNC 0101</p> </div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Tue, 10 Jun 2025 18:03:10 +0000 Naomi Grosman 3814 at /institute-for-quantum-computing IQC Math and CS seminar featuring Junqiao Lin /institute-for-quantum-computing/events/iqc-math-and-cs-seminar-featuring-junqiao-lin <span class="field field--name-title field--type-string field--label-hidden">IQC Math and CS seminar featuring Junqiao Lin</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/ngrosman" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">Naomi Grosman</span></span> <span class="field field--name-created field--type-created field--label-hidden">Thu, 05/29/2025 - 13:03</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-4405e018-30d8-4289-831c-5ea2755cff84" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>MIPco=coRE and generalized compression framework</h2> <p>Junqiao Lin | Centrum Wiskunde & Informatica (CWI)</p> <p>Nonlocal games is a mathematical model used to model entanglement. Recently, Ji et al shows that estimating the optimal success rate for a nonlcoal game under the quantum (tensor) model is uncomputable in the celebrated result MIP*=RE result. A key part of this breakthrough involves a compression theorem for nonlocal games, a way to shrink the question and answer size of the game while preserving the optimal success rate to some degree.</p> <p>In this talk, I will introduce the generalized compression framework, a generalization of the compression argument used in the MIP*=RE theorem, which could be applied to other computation problems unrelated to nonlocal games. I will explore how this framework can be used to prove the coRE-completeness of the complexity class MIPco, an MIP protocol where provers are allowed access to the commuting operator model of entanglement.</p> <p>This talk is based on the upcoming paper MIPco=coRE. </p> <h3>Location</h3> <ul><li> <p>QNC 1201</p> </li> <li> <p><a href="https://uwaterloo.zoom.us/j/99224200124?pwd=moWgVv6T223hBmjUGxc6TcgTFeTIet.1">Online on Zoom</a></p> <ul><li> <p>Meeting ID: 992 2420 0124</p> </li> <li> <p>Passcode: 983537</p> </li> </ul></li> </ul></div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Thu, 29 May 2025 17:03:48 +0000 Naomi Grosman 3813 at /institute-for-quantum-computing Operator Algebras and Quantum Information /institute-for-quantum-computing/events/operator-algebras-and-quantum-information <span class="field field--name-title field--type-string field--label-hidden">Operator Algebras and Quantum Information</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/ngrosman" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">Naomi Grosman</span></span> <span class="field field--name-created field--type-created field--label-hidden">Tue, 05/27/2025 - 11:25</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div class="layout__region layout__region--first"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <p>In the past decade several remarkable interactions between operator algebras and quantum information theory have been discovered. Some of the fundamental concepts of quantum information such as quantum entanglement, nonlocality, channel capacity, quantum entropy and cryptography are shown to be closely related to operator algebras and functional analysis. Aside from their theoretical importance, operator algebras naturally model hybrid classical-quantum systems and numerous modern-day architectures that encode quantum information in infinite-dimensional quantum systems.</p> <p>The Fields Institute for Research in Mathematical Science's inaugural Operator Algebras and Quantum Information conference will be in honour of Vern Paulsen on the occasion of his recent retirement. He made significant contributions to the field and helped train and influence a remarkable number of young researchers.</p> <h2>Organizing committee</h2> <ul><li><a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="79ce1991-7cee-44bd-96fc-76238005e2df" href="/institute-for-quantum-computing/contacts/michael-brannan">Michael Brannan</a> - University of ݮƵ</li> <li>Jason Crann - Carleton University</li> <li>David Kribs - University of Guelph</li> <li>Mizanur Rahaman - Chalmers University of Technology</li> <li><a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="d4a9bf9e-4999-4aa4-b2e0-2f6d6911c6dc" href="/institute-for-quantum-computing/research/groups/william-slofstra">William Slofstra</a> - University of ݮƵ</li> </ul><h2>Location</h2> <p>QNC 0101</p> </div> </div> </div> <div class="block block-layout-builder block-inline-blockuw-cbl-call-to-action"> <div class="uw-cta "> <div class="uw-cta__center-wrapper"> <aside class="uw-cta__aside org-default"><a href="http://www.fields.utoronto.ca/activities/24-25/operator-algebras-quantum-information" class="uw-cta__link"> <div class="uw-cta__wrapper"> <div class="call-to-action-theme-org-default"> <div class="uw-cta__text uw-cta__text--small">LEARN MORE AND</div> <div class="uw-cta__text uw-cta__text--big">Register for the workshop</div> </div> </div> </a> </aside></div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Tue, 27 May 2025 15:25:41 +0000 Naomi Grosman 3812 at /institute-for-quantum-computing IQC PhD seminar featuring Jiahui Chen /institute-for-quantum-computing/events/iqc-phd-seminar-featuring-jiahui-chen <span class="field field--name-title field--type-string field--label-hidden">IQC PhD seminar featuring Jiahui Chen</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/ngrosman" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">Naomi Grosman</span></span> <span class="field field--name-created field--type-created field--label-hidden">Fri, 05/23/2025 - 11:43</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-90b46ed5-f011-4bf0-aaa9-f65b7954c8ec" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>Engineering robust and precise effective Hamiltonians</h2> <p>Jiahui Chen</p> <p>Quantum control is essential for implementing high-fidelity operations in quantum computing, simulation, and sensing. Achieving robust control in realistic systems requires techniques that take into account limitations in the control signals, imperfections in implementations, and dispersions in system Hamiltonians.</p> <p>I will introduce a general framework for robust quantum control design based on Hamiltonian engineering using Average Hamiltonian Theory (AHT). This framework allows us to characterize system controllability, systematically incorporate robustness to common control errors, and design control sequences that generate desired nonzero zeroth- and higher-order terms in the Magnus expansion.</p> <p>It also accounts for higher-order corrections and cross terms, enabling comprehensive error analysis. The methods are illustrated with simple examples in gate design, quantum simulation, and sensing.</p> <h3>Location</h3> <p>RAC2 1101</p> </div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Fri, 23 May 2025 15:43:37 +0000 Naomi Grosman 3803 at /institute-for-quantum-computing IQC Math and CS seminar featuring Yangjing Dong /institute-for-quantum-computing/events/iqc-math-and-cs-seminar-featuring-yangjing-dong <span class="field field--name-title field--type-string field--label-hidden">IQC Math and CS seminar featuring Yangjing Dong</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/ngrosman" typeof="schema:Person" property="schema:name" datatype="" xml:lang="">Naomi Grosman</span></span> <span class="field field--name-created field--type-created field--label-hidden">Tue, 05/20/2025 - 17:55</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-cf2d614c-d755-4cab-967c-43dbe9c7cfdf" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>On the Computational Power of QAC0 with Barely Superlinear Ancillae</h2> <p>Yangjing Dong | Nanjing University</p> <p>$\mathrm{QAC}^0$ is the family of constant-depth polynomial-size quantum circuits consisting of arbitrary single qubit unitaries and multi-qubit Toffoli gates. It was introduced by Moore [arXiv: 9903046] as a quantum counterpart of $\mathrm{AC}^0$, along with the conjecture that $\mathrm{QAC}^0$ circuits can not compute PARITY. In this work we make progress on this long standing conjecture: we show that any depth-$d$ $\mathrm{QAC}^0$ circuit requires $n^{1+3^{-d}}$ ancillae to compute a function with approximate degree $\Theta(n)$, which includes PARITY, MAJORITY and $\mathrm{MOD}_k$. We further establish superlinear lower bounds on quantum state synthesis and quantum channel synthesis. This is the first superlinear lower bound on the super-linear sized $\mathrm{QAC}^0$. Regarding PARITY, we show that any further improvement on the size of ancillae to $n^{1+\exp(-o(d))}$ would imply that PARITY $\not\in$ QAC0. These lower bounds are derived by giving low-degree approximations to $\mathrm{QAC}^0$ circuits. We show that a depth-$d$ $\mathrm{QAC}^0$ circuit with $a$ ancillae, when applied to low-degree operators, has a degree $(n+a)^{1-3^{-d}}$ polynomial approximation in the spectral norm. This implies that the class $\mathrm{QLC}^0$, corresponding to linear size $\mathrm{QAC}^0$ circuits, has approximate degree $o(n)$. This is a quantum generalization of the result that $\mathrm{LC}^0$ circuits have approximate degree $o(n)$ by Bun, Robin, and Thaler [SODA 2019]. Our result also implies that $\mathrm{QLC}^0\neq\mathrm{NC}^1$.</p> <h3>Location</h3> <ul><li> <p><a href="https://uwaterloo.zoom.us/j/92424576407?pwd=bOcaloFtMSeQAObizI2aRkyWTJPZaq.1">Online on Zoom</a></p> <ul><li> <p>Meeting ID: 924 2457 6407</p> </li> <li> <p>Passcode: 318885</p> </li> </ul></li> </ul></div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Tue, 20 May 2025 21:55:19 +0000 Naomi Grosman 3793 at /institute-for-quantum-computing IQC Math and CS seminar featuring Prem Nigam Kar /institute-for-quantum-computing/events/iqc-math-and-cs-seminar-featuring-prem-nigam-kar <span class="field field--name-title field--type-string field--label-hidden">IQC Math and CS seminar featuring Prem Nigam Kar</span> <span class="field field--name-uid field--type-entity-reference field--label-hidden"><span lang="" about="/institute-for-quantum-computing/users/tcvmudzo" typeof="schema:Person" property="schema:name" datatype="" content="tcvmudzo" xml:lang="">Takudzwa Chipo…</span></span> <span class="field field--name-created field--type-created field--label-hidden">Fri, 05/09/2025 - 11:25</span> <section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none uw-section-alignment--top-align-content layout layout--uw-2-col larger-right"><div class="layout__region layout__region--first"> <div class="block block-layout-builder block-inline-blockuw-cbl-banner-images"> <article id="banner1-2100e4bc-0aa7-4b83-93ca-2a784e1830bf" class="card card__banner "><div class="card__body"> <div class="card__banner--image uw-text-overlay--none"> <!--If banner text overlay is split then always show the H1 in the top white bar. --> <div class="card__banner--media"> <picture class="uw-picture"><!--[if IE 9]><video style="display: none;"><![endif]--><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_large/public/uploads/images/untitled-2-2.png?itok=X5vj9l4J 1x" media="all and (min-width: 63.19em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_large/public/uploads/images/untitled-2-2.png?itok=oZtgAYHw 1x" media="all and (min-width: 49.81em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_medium/public/uploads/images/untitled-2-2.png?itok=1vvVumud 1x" media="all and (min-width: 30em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_small/public/uploads/images/untitled-2-2.png?itok=SbyXGMuJ 1x" media="all and (min-width: 25em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_media_x_small/public/uploads/images/untitled-2-2.png?itok=_0PWodRp 1x" media="all and (min-width: 15em)" type="image/png"></source><source srcset="/institute-for-quantum-computing/sites/default/files/styles/uw_is_portrait/public/uploads/images/untitled-2-2.png?itok=k9GeLqf9 1x" media="all and (min-width: 1em)" type="image/png"></source><!--[if IE 9]></video><![endif]--><img class="uw-picture__fallback" src="/institute-for-quantum-computing/sites/default/files/styles/large/public/uploads/images/untitled-2-2.png?itok=GmFMAfID" alt="" /></picture></div> <div class="card__banner--caption uw_para_image_banner"> <div class="card__banner--text-align"> </div> </div> </div> </div> </article></div> </div> <div class="layout__region layout__region--second"> <div class="uw-text-align--left block block-layout-builder block-inline-blockuw-cbl-copy-text"> <div class="uw-copy-text"> <div class="uw-copy-text__wrapper "> <h2>NPA Hierarchy for Quantum Isomorphism and Homomorphism Indistinguishability</h2> <p>Prem Nigam Kar | Technical University of Denmark</p> <p>Mančinska and Roberson connected the seemingly unrelated fields of nonlocal games and homomorphism indistinguishability by showing that there is a perfect quantum commuting strategy for the graph isomorphism game between two graphs if and only if they admit the same number of homomorphisms from all planar graphs.</p> <p>In this talk, we shall see that relaxations of quantum isomorphism of graphs arising from the NPA hierarchy can be characterized as homomorphism indistinguishability relations over an appropriate class of planar graphs. By combining this result with the convergence of the NPA hierarchy, we are able to obtain an alternative proof of the homomorphism indistinguishability characterization of quantum isomorphism avoiding the use of quantum groups.</p> <p>Another consequence of our main result is the existence of a randomized polynomial time algorithm deciding exact feasibility of each level of the NPA hierarchy for quantum isomorphism.</p> <h3>Location</h3> <ul><li> <p>QNC 1201</p> </li> <li> <p><a href="https://uwaterloo.zoom.us/j/97661270572?pwd=lfzt2Ryl7FDLZ3TKhYJkovMcHuCMCy.1">Online on Zoom</a></p> <ul><li> <p>Meeting ID: 976 6127 0572</p> </li> <li> <p>Passcode: 498117</p> </li> </ul></li> </ul></div> </div> </div> </div> </section><section class="uw-contained-width uw-section-spacing--default uw-section-separator--none uw-column-separator--none layout layout--uw-1-col"><div> </div> </section> Fri, 09 May 2025 15:25:16 +0000 Takudzwa Chipo Valerie Mudzongo 3791 at /institute-for-quantum-computing