Talks

9169 - 9180 of 16889 Results

Defects: A new window into topological quantum matter

Maissam Barkeshli University of California, Santa Barbara

October 01, 2014

PIRSA:14100048
The Topology of Information Flow

Jamie Vicary University of Oxford

September 30, 2014

PIRSA:14090076
Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits

Eduardo Mucciolo University of Central Florida

September 30, 2014

PIRSA:14090028

Condensed Matter
PHYS 781 - Lecture 4

Niayesh Afshordi University of Waterloo

September 30, 2014

PIRSA:14090085
3d Gravity, Universality and Poincare Series

September 30, 2014

PIRSA:14090005
ADMX: The Axion Dark Matter Experiment

Gray Rybka University of Washington

September 30, 2014

PIRSA:14090067

Particle Physics
From Black Holes to Big Bang, and Back

Niayesh Afshordi University of Waterloo

September 30, 2014

PIRSA:14090088
PHYS 781 - Lecture 3

Niayesh Afshordi University of Waterloo

September 26, 2014

PIRSA:14090087
14/15 PSI Quantum Theory-15

Joseph Emerson Institute for Quantum Computing (IQC)

September 26, 2014

PIRSA:14090060
14/15 PSI - Relativity- Lecture 15

Neil Turok University of Edinburgh

September 26, 2014

PIRSA:14090064
PHYS 781 - Lecture 2

Niayesh Afshordi University of Waterloo

September 25, 2014

PIRSA:14090086
14/15 PSI Quantum Theory-14

Joseph Emerson Institute for Quantum Computing (IQC)

September 25, 2014

PIRSA:14090059

Defects: A new window into topological quantum matter

Maissam Barkeshli University of California, Santa Barbara

October 01, 2014

PIRSA:14100048

Topologically ordered states, such as the fractional quantum Hall (FQH) states, are quantum states of matter with various exotic properties, including quasiparticles with fractional quantum numbers and fractional statistics, and robust topology-dependent ground state degeneracies. In this talk, I will describe a new aspect of topological states: their extrinsic defects. These include extrinsically imposed point-like or line-like defects that couple to the topological properties of the state in non-trivial ways. The extrinsic point defects localize topologically protected "parafermion" zero modes, which generalize the notion of Majorana fermion zero modes, and provide a new direction for realizing non-Abelian quantum statistics and topological quantum computation. The line defects allow direct quantum mechanical coupling between electrons and fractionalized anyons, leading to new ways to probe fractionalization. After describing the conceptual framework, I will focus on a specific set of experimental proposals, using conventional bilayer FQH states, to detect parafermion zero modes and to directly observe the long-predicted topological ground state degeneracy of FQH states. In the end I will comment on other ways in which extrinsic defects provide a new window into fractionalization.
The Topology of Information Flow

Jamie Vicary University of Oxford

September 30, 2014

PIRSA:14090076

I will outline a new topological foundation for computation, and show how it gives rise to a unified treatment of classical encryption and quantum teleportation, and a strong classical model for many quantum phenomena. This work connects to some other interesting topics, including quantum field theory, classical combinatorics, thermodynamics, Morse theory and higher category theory, which I will introduce in an elementary way.
Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits

Eduardo Mucciolo University of Central Florida

September 30, 2014

PIRSA:14090028

Condensed Matter

We show that for a system evolving unitarily under a stochastic quantum circuit, the notions of irreversibility, universality of computation, and entanglement are closely related. As the state of the system evolves from an initial product state, it becomes increasingly entangled until entanglement reaches a maximum. We define irreversibility as the failure to find a circuit that disentangles a maximally entangled state. We show that irreversibility occurs when maximally entangled states are generated with a quantum circuit formed by gates from a universal quantum computation set. We find that irreversibility is also associated to a Wigner-Dyson statistics in the fluctuations of spacings between adjacent eigenvalues of the system’s reduced density matrix. In contrast, when the system is evolved with a non-universal set of gates, the statistics of the entanglement spacing deviates from Wigner-Dyson and the disentangling algorithm succeeds. We discuss how these findings open a new way to characterize non-integrability in quantum systems.
PHYS 781 - Lecture 4

Niayesh Afshordi University of Waterloo

September 30, 2014

PIRSA:14090085
3d Gravity, Universality and Poincare Series

September 30, 2014

PIRSA:14090005

Modular invariance plays an important role in the AdS3/CFT2 correspondence. Using modular invariance, I discuss under what conditions a 2d CFT shows a Hawking-Page phase transition in the large c limit, and what this implies for the range of validity of the Cardy formula and the universality of its spectrum. I will also discuss partition functions obtained by summing over the modular group, how their properties are compatible with their gravity interpretation, and briefly touch on implications for the existence of pure gravity.
ADMX: The Axion Dark Matter Experiment

Gray Rybka University of Washington

September 30, 2014

PIRSA:14090067

Particle Physics

Axions are an exceptionally well-motivated dark matter candidate in addition to being a consequence of the Peccei-Quinn solution to the strong CP problem. ADMX (Axion Dark Matter eXperiment) has recently been selected as the axion search for the US DOE Second-Generation Dark Matter Program. I will discuss the imminent upgrade of ADMX to a definitive search for micro-eV mass dark matter axions as well as the ongoing research and development of new technologies to expand the reach of ADMX to the entire plausible dark matter axion mass range.
From Black Holes to Big Bang, and Back

Niayesh Afshordi University of Waterloo

September 30, 2014

PIRSA:14090088

By now, both black hole astrophysics and big bang cosmology are empirically well-established disciplines of physics and astronomy. They are also the only circumstances in nature where Einstein's general relativity can be seen in its full glory, and yet contain within them, its eventual and inevitable folly. Here, I will outline subtle lines evidence for why a phenomenologically successful description of big bang cosmology and black hole horizons may be intimately connected. These lines include a holographic description of big bang, thermal tachyacoustic cosmology, and the firewall controversy. Astrophysical observations, ranging from CMB and dark energy probes, to astrophysical neutrinos could shed further light on these potential connections.
PHYS 781 - Lecture 3

Niayesh Afshordi University of Waterloo

September 26, 2014

PIRSA:14090087
14/15 PSI Quantum Theory-15

Joseph Emerson Institute for Quantum Computing (IQC)

September 26, 2014

PIRSA:14090060
14/15 PSI - Relativity- Lecture 15

Neil Turok University of Edinburgh

September 26, 2014

PIRSA:14090064
PHYS 781 - Lecture 2

Niayesh Afshordi University of Waterloo

September 25, 2014

PIRSA:14090086
14/15 PSI Quantum Theory-14

Joseph Emerson Institute for Quantum Computing (IQC)

September 25, 2014

PIRSA:14090059

Title	Date	Collection	Type	Info
Defects: A new window into topological quantum matter	2014‑10‑01	Colloquium	Scientific Series	View details
The Topology of Information Flow	2014‑09‑30	Quantum Foundations	Scientific Series	View details
Irreversibility and Entanglement Spectrum Statistics in Quantum Circuits	2014‑09‑30	Quantum Matter	Scientific Series	View details
PHYS 781 - Lecture 4	2014‑09‑30	PHYS 781 - Fundamentals of Astrophysics	Course	View details
3d Gravity, Universality and Poincare Series	2014‑09‑30	Quantum Fields and Strings	Scientific Series	View details
ADMX: The Axion Dark Matter Experiment	2014‑09‑30	Particle Physics	Scientific Series	View details
From Black Holes to Big Bang, and Back	2014‑09‑30	Cosmology and Gravitation	Scientific Series	View details
PHYS 781 - Lecture 3	2014‑09‑26	PHYS 781 - Fundamentals of Astrophysics	Course	View details
14/15 PSI Quantum Theory-15	2014‑09‑26	14/15 PSI - Quantum Theory	Course	View details
14/15 PSI - Relativity- Lecture 15	2014‑09‑26	14/15 PSI -Relativity	Course	View details
PHYS 781 - Lecture 2	2014‑09‑25	PHYS 781 - Fundamentals of Astrophysics	Course	View details
14/15 PSI Quantum Theory-14	2014‑09‑25	14/15 PSI - Quantum Theory	Course	View details

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