Search Talks

Search results

2377 - 2388 of 16736 Results

Intrinsically gapless symmetry-protected topology
- Andrew Potter University of British Columbia
- Andrew Potter
November 16, 2022

PIRSA:22110075
Condensed Matter
Emergent anomalies and generalized Luttinger theorems in metals and semimetals

Anton Burkov University of Waterloo
November 16, 2022

PIRSA:22110074
Condensed Matter
Statistical Physics - Lecture 221116

November 16, 2022

PIRSA:22110013
Measurement as a shortcut to long-range entangled quantum matter

Tsung-Cheng Lu (Peter) University of Maryland, College Park
November 15, 2022

PIRSA:22110073
Condensed Matter
QFT2 - Quantum Electrodynamics - Afternoon Lecture

Cliff Burgess McMaster University
November 15, 2022

PIRSA:22110040
Particle Physics

Quantum Fields and Strings
A minimalist's approach to the physics of emergence

Liujun Zou National University of Singapore
November 15, 2022

PIRSA:22110072
Condensed Matter
dS in N=2 super Liouville

Beatrix Muehlmann McGill University
November 15, 2022

PIRSA:22110021
Quantum Fields and Strings
New ALP probes from light meson decays

Stefania Gori University of California, Santa Cruz
November 15, 2022

PIRSA:22110056
Particle Physics
Synthesis of many-body quantum states using group-IV (Ge/Si) quantum devices

Joe Salfi University of British Columbia
November 15, 2022

PIRSA:22110071
Condensed Matter
Quantum Field Theory II - Lecture 221115

Francois David CEA Saclay

November 15, 2022

PIRSA:22110004
Functional renormalization group formalism for non-Fermi liquids and the antiferromagnetic quantum critical metal

Sung-Sik Lee McMaster University
November 15, 2022

PIRSA:22110069
Condensed Matter
QFT2 - Quantum Electrodynamics - Morning Lecture
November 15, 2022

PIRSA:22110035
Quantum Fields and Strings

Intrinsically gapless symmetry-protected topology
- Andrew Potter University of British Columbia
- Andrew Potter
November 16, 2022

PIRSA:22110075
Condensed Matter
While sharply-quantized topological features are conventionally associated with gapped phases of matter, there are a growing number of examples of gapless systems with topologically protected edge states. A particularly striking set of examples are "intrinsically gapless" symmetry-protected topological states (igSPTs), which host topological surface states that could not arise in a gapped system with the same symmetries. Examples include familiar non-interacting Weyl semimetals with Fermi arc surface states, as well as more exotic examples like deconfined quantum critical points with topological edge states. In this talk, I will discuss recent progress in formally understanding the bulk-boundary correspondence of strongly-interacting igSPTs using tools from group cohomology. In these examples, the gapless-ness of the bulk and presence of topological surface states can be understood in a unified way due to the presence of an emergent anomaly. Our formalism allows construction of lattice-models with such emergent anomalies whose topological properties can be deduced exactly.
Emergent anomalies and generalized Luttinger theorems in metals and semimetals

Anton Burkov University of Waterloo
November 16, 2022

PIRSA:22110074
Condensed Matter
Luttinger's theorem connects a basic microscopic property of a given metallic crystalline material, the number of electrons per unit cell, to the volume, enclosed by its Fermi surface, which defines its low-energy observable properties. Such statements are valuable since, in general, deducing a low-energy description from microscopics, which may perhaps be regarded as the main problem of condensed matter theory, is far from easy. In this talk I will present a unified framework, which allows one to discuss Luttinger theorems for ordinary metals, as well as closely analogous exact statements for topological (semi)metals, whose low-energy description contains either discrete point or continuous line nodes. This framework is based on the 't Hooft anomaly of the emergent charge conservation symmetry at each point on the Fermi surface, a concept recently proposed by Else, Thorngren and Senthil [Phys. Rev. X {\bf 11}, 021005 (2021)]. We find that the Fermi surface codimension $p$ plays a crucial role for the emergent anomaly. For odd $p$, such as ordinary metals ($p=1$) and magnetic Weyl semimetals ($p=3$), the emergent symmetry has a generalized chiral anomaly. For even $p$, such as graphene and nodal line semimetals (both with $p=2$), the emergent symmetry has a generalized parity anomaly. When restricted to microscopic symmetries, such as $U(1)$ and lattice symmetries, the emergent anomalies imply (generalized) Luttinger theorems, relating Fermi surface volume to various topological responses. The corresponding topological responses are the charge density for $p=1$, Hall conductivity for $p=3$, and polarization for $p=2$. As a by-product of our results, we clarify exactly what is anomalous about the surface states of nodal line semimetals.
Statistical Physics - Lecture 221116

November 16, 2022

PIRSA:22110013
Measurement as a shortcut to long-range entangled quantum matter

Tsung-Cheng Lu (Peter) University of Maryland, College Park
November 15, 2022

PIRSA:22110073
Condensed Matter
The preparation of long-range entangled states using unitary circuits is limited by Lieb-Robinson bounds, but circuits with projective measurements and feedback (``adaptive circuits'') can evade such restrictions. We introduce three classes of local adaptive circuits that enable low-depth preparation of long-range entangled quantum matter characterized by gapped topological orders and conformal field theories (CFTs). The three classes are inspired by distinct physical insights, including tensor-network constructions, multiscale entanglement renormalization ansatz (MERA), and parton constructions. A large class of topological orders, including chiral topological order, can be prepared in constant depth or time, and one-dimensional CFT states and non-abelian topological orders with both solvable and non-solvable groups can be prepared in depth scaling logarithmically with system size. We also build on a recently discovered correspondence between symmetry-protected topological phases and long-range entanglement to derive efficient protocols for preparing symmetry-enriched topological order and arbitrary CSS (Calderbank-Shor-Steane) codes. Our work illustrates the practical and conceptual versatility of measurement for state preparation.
QFT2 - Quantum Electrodynamics - Afternoon Lecture

Cliff Burgess McMaster University
November 15, 2022

PIRSA:22110040
Particle Physics

Quantum Fields and Strings
This course uses quantum electrodynamics (QED) as a vehicle for covering several more advanced topics within quantum field theory, and so is aimed at graduate students that already have had an introductory course on quantum field theory. Among the topics hoped to be covered are: gauge invariance for massless spin-1 particles from special relativity and quantum mechanics; Ward identities; photon scattering and loops; UV and IR divergences and why they are handled differently; effective theories and the renormalization group; anomalies.
A minimalist's approach to the physics of emergence

Liujun Zou National University of Singapore
November 15, 2022

PIRSA:22110072
Condensed Matter
One of the central themes of condensed matter physics is the emergence of universality classes. In general, it is highly complex to determine which universality class emerges in a quantum matter based on its microscopic properties. In this talk, I will argue that the perspective of quantum anomaly provides powerful insights into the understanding of the landscape of universality classes that can emerge in a quantum matter, and I will present some interesting applications. Along the way, I will discuss the notions of entanglement-enabled symmetry-breaking orders, non-Lagrangian quantum criticality, quantum spin liquids beyond the usual parton description, etc.
dS in N=2 super Liouville

Beatrix Muehlmann McGill University
November 15, 2022

PIRSA:22110021
Quantum Fields and Strings
In my talk I will discuss the Euclidean gravitational path integral of N=2 (timelike) Liouville theory on a two-sphere. We view N= 2 Liouville as a gauge fixed form of a 2d supergravity theory coupled to an N=2 superconformal field theory. N=2 super Liouville admits a positive cosmological constant. I will discuss and contrast the results of supersymmetric localization and the explicit higher-loop evaluation of the path integral around it's dS_2 saddle.

Zoom Link: https://pitp.zoom.us/j/91448729065?pwd=TmJSOGg4dkNxMVJsTWxRRHBYZnVoZz09
New ALP probes from light meson decays

Stefania Gori University of California, Santa Cruz
November 15, 2022

PIRSA:22110056
Particle Physics
Rare meson decays are among the most sensitive probes of both heavy and light new physics. Among them, new physics searches using kaons and pions benefit from their small total decay widths and the availability of very large datasets. In this talk, we first give an overview of new opportunities to search for axion-like particles (ALPs) in light meson decays. Second, we revisit the theory and constraints on ALPs interacting with leptons, pointing out the relevance of charged current meson and W decays to ALPs. This is particularly prominent in models where the ALP couples in an isospin-violating way. Finally, we highlight the role of the future PIONEER experiment in probing these new charged current pion decays to ALPs.

Zoom Link: https://pitp.zoom.us/j/98376159809?pwd=eDNHd1NhTUlVTmV4Y1RONjllNTNPdz09
Synthesis of many-body quantum states using group-IV (Ge/Si) quantum devices

Joe Salfi University of British Columbia
November 15, 2022

PIRSA:22110071
Condensed Matter
Quantum dot arrays are an emerging system to synthesize controlled many-body quantum states for quantum simulation and computation. When cooled to a low temperature, each quantum dot acts as a site on which the number of half-integer spin particles can be controlled using voltages applied to gates, not unlike the gates on classical transistors. Moreover, the spin can be controlled and measured with the help of patterns of gates. It has recently been shown that tunnel couplings between individual sites can be controlled using the same gates to emulate a Hubbard model (unlike other systems i.e., superconductors, trapped ions, Rydberg atoms, etc), making it possible to program a many-body system using only voltages applied to gates, and that the spin can be initialized, controlled and read out on arrays of 4 to 6 quantum dots like a conventional quantum computer (unlike cold atoms in optical lattices). It has also recently been shown that the coherence times of the spin degree of freedom can be as long as 10 ms in this material system, and that the quantum dots can be proximized to superconductors. In this talk I will describe our efforts towards synthesis of interesting quantum states using this platform, at our lab in University of British Columbia.
Quantum Field Theory II - Lecture 221115

Francois David CEA Saclay

November 15, 2022

PIRSA:22110004
Functional renormalization group formalism for non-Fermi liquids and the antiferromagnetic quantum critical metal

Sung-Sik Lee McMaster University
November 15, 2022

PIRSA:22110069
Condensed Matter
We develop a field-theoretic functional renormalization group formalism for field theories of metals that include all gapless modes around the Fermi surface. Due to the presence of intrinsic scales (Fermi momenta), the usual notion of scale invariance and renormalizable field theory need to be generalized. The formalism is applied to the non-Fermi liquid that arises at the anti-ferromagnetic quantum critical point in two space dimensions. We identify the interacting non-Fermi liquid fixed point in the space of coupling functions, and extract the universal scaling behaviour of the normal state and the pathway to the superconducting state at low energies.
QFT2 - Quantum Electrodynamics - Morning Lecture
November 15, 2022

PIRSA:22110035
Quantum Fields and Strings
This course uses quantum electrodynamics (QED) as a vehicle for covering several more advanced topics within quantum field theory, and so is aimed at graduate students that already have had an introductory course on quantum field theory. Among the topics hoped to be covered are: gauge invariance for massless spin-1 particles from special relativity and quantum mechanics; Ward identities; photon scattering and loops; UV and IR divergences and why they are handled differently; effective theories and the renormalization group; anomalies.

Title	Speaker Profile(s)	Date	Collection	Type	Info
Intrinsically gapless symmetry-protected topology	Andrew Potter	2022‑11‑16	Quantum Matter Workshop	Conference	View details
Emergent anomalies and generalized Luttinger theorems in metals and semimetals		2022‑11‑16	Quantum Matter Workshop	Conference	View details
Statistical Physics - Lecture 221116		2022‑11‑16	Statistical Physics (2022/2023)	Course	View details
Measurement as a shortcut to long-range entangled quantum matter		2022‑11‑15	Quantum Matter Workshop	Conference	View details
QFT2 - Quantum Electrodynamics - Afternoon Lecture		2022‑11‑15	Special Topics in Physics - QFT2: Quantum Electrodynamics (Cliff Burgess)	Course	View details
A minimalist's approach to the physics of emergence		2022‑11‑15	Quantum Matter Workshop	Conference	View details
dS in N=2 super Liouville		2022‑11‑15	Quantum Fields and Strings	Scientific Series	View details
New ALP probes from light meson decays		2022‑11‑15	Particle Physics	Scientific Series	View details
Synthesis of many-body quantum states using group-IV (Ge/Si) quantum devices		2022‑11‑15	Quantum Matter Workshop	Conference	View details
Quantum Field Theory II - Lecture 221115		2022‑11‑15	Quantum Field Theory II (2022/2023)	Course	View details
Functional renormalization group formalism for non-Fermi liquids and the antiferromagnetic quantum critical metal		2022‑11‑15	Quantum Matter Workshop	Conference	View details
QFT2 - Quantum Electrodynamics - Morning Lecture		2022‑11‑15	Special Topics in Physics - QFT2: Quantum Electrodynamics (Cliff Burgess)	Course	View details

Search Talks

Format results