Talks

12625 - 12636 of 20118 Results

Quantum Spin Liquids,Density Matrix Renormalization Group, and Entanglement

Leon Balents University of California, Santa Barbara

May 09, 2013

PIRSA:13050040

Condensed Matter
Searching for Spin Liquids

Steven White University of California, Irvine

May 09, 2013

PIRSA:13050039

High Energy Physics

Condensed Matter
Entangled states of quantum matter

Subir Sachdev Harvard University

May 08, 2013

PIRSA:13050038

Condensed Matter
Holographic insights into quantum critical transport: from branes to Bose-Hubbard

May 08, 2013

PIRSA:13050037

Condensed Matter
Quantum renormalization group and AdS/CFT

Sung-Sik Lee McMaster University

May 08, 2013

PIRSA:13050036

High Energy Physics
Propagation of entanglement in strongly coupled systems from gravity

Hong Liu Massachusetts Institute of Technology (MIT) - Department of Physics

May 08, 2013

PIRSA:13050035

General Relativity & Quantum Cosmology
Thermodynamical Property of Entanglement Entropy for Excited States

Tadashi Takayanagi Yukawa Institute for Theoretical Physics

May 08, 2013

PIRSA:13050034

Condensed Matter
Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Xie Chen California Institute of Technology

May 07, 2013

PIRSA:13050033

High Energy Physics
Limitations on the psi-epistemic view of quantum states

Owen Maroney

May 07, 2013

PIRSA:13050018
3D topological lattice models with topologically ordered surface states

Fiona Burnell University of Minnesota

May 07, 2013

PIRSA:13050032

Condensed Matter
Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Cenke Xu University of California, Santa Barbara

May 07, 2013

PIRSA:13050031

High Energy Physics
Majorana Ghosts: From topological superconductor to the origin of neutrino mass, three generations and their mass mixing

Zheng-Cheng Gu Chinese University of Hong Kong

May 07, 2013

PIRSA:13050052

Condensed Matter

Quantum Spin Liquids,Density Matrix Renormalization Group, and Entanglement

Leon Balents University of California, Santa Barbara

May 09, 2013

PIRSA:13050040

Condensed Matter

I will review recent work in our group using Density Matrix Renormalization Group (DMRG) to search for and study quantum spin liquid and topologically ordered states in two dimensional model Hamiltonians. This proves an efficient way to study these phases in semi-realistic situations. I will try to draw lessons from several studies and theoretical considerations.
Searching for Spin Liquids

Steven White University of California, Irvine

May 09, 2013

PIRSA:13050039

High Energy Physics

Condensed Matter
Entangled states of quantum matter

Subir Sachdev Harvard University

May 08, 2013

PIRSA:13050038

Condensed Matter

Theorists have been studying and classifying entanglement in many-particle quantum states for many years. In the past few years, experiments on such states have finally appeared, generating much excitement. I will describe experimental observations on magnetic insulators, ultracold atoms, and high temperature superconductors, and their invigorating influence on our theoretical understanding.
Holographic insights into quantum critical transport: from branes to Bose-Hubbard

May 08, 2013

PIRSA:13050037

Condensed Matter

We discuss the general features of charge transport of quantum critical points described by CFTs in 2+1D. Our main tool is the AdS/CFT correspondence, but we will make connections to standard field theory results and to recent quantum Monte Carlo data. We emphasize the importance of poles and zeros of the response functions. In the holographic setting, these are the discrete quasinormal modes of a black hole/brane; they map to the excitations of the CFT. We further describe the role of particle-vortex or S-duality on the conductivity, which is argued to obey two powerful sum rules.
References (with S. Sachdev): arXiv:1210.4166 (PRB 12); arXiv:1302.0847 (PRB 13)
Quantum renormalization group and AdS/CFT

Sung-Sik Lee McMaster University

May 08, 2013

PIRSA:13050036

High Energy Physics

In this talk, I will discuss about the notion of quantum renormalization group, and explain how (D+1)-dimensional gravitational theories naturally emerge as dual descriptions for D-dimensional quantum field theories. It will be argued that the dynamical gravitational field in the bulk encodes the entanglement between low energy modes and high energy modes of the corresponding quantum field theory.
Propagation of entanglement in strongly coupled systems from gravity

Hong Liu Massachusetts Institute of Technology (MIT) - Department of Physics

May 08, 2013

PIRSA:13050035

General Relativity & Quantum Cosmology
Thermodynamical Property of Entanglement Entropy for Excited States

Tadashi Takayanagi Yukawa Institute for Theoretical Physics

May 08, 2013

PIRSA:13050034

Condensed Matter

We will point out that there is a universal thermodynamical property of entanglement entropy for excited states. We will derive this by using the AdS/CFT correspondence in any dimension. We will also directly confirm this property from direct field theoretic calculations in two dimensions. We will define a new quantity called entanglement density by taking derivatives of entanglement entropy with respect to the shape of subsystem. We will show that this quantity coincides with the energy density by taking the small subsystem limit and show that this is another equivalent statement of the thermodynamical property.
Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Xie Chen California Institute of Technology

May 07, 2013

PIRSA:13050033

High Energy Physics

In quantum systems with symmetry, the same topological phase can be enriched by symmetry in different ways, resulting in different symmetry transformations of the superselection sectors in the phase. However, not all symmetry transformations are allowed on the superselection sectors in topological phases in purely 2D systems. In this talk, I will discuss some examples of such symmetry enrichment of topological phases, which seem to be consistent with the fusion and braiding rules of the superselection sectors in the theory but are nonetheless impossible to realize in 2D. Interestingly, we show further that they can be realized on the surface of a 3D gapped system with a topologically trivial bulk.
Limitations on the psi-epistemic view of quantum states

Owen Maroney

May 07, 2013

PIRSA:13050018

The "psi-epistemic" view is that the quantum state does not represent a state of the world, but a state of knowledge about the world. It is motivated, in part, by the observation of qualitative similarities between characteristic properties of non-orthogonal quantum wavefunctions and between overlapping classical probability distributions. It might be suggested that this gives a natural explanation for these properties, which seem puzzling for the alternative "psi-ontic" view. I will examine two such similarities, quantum state overlap and quantum state discrimination, and ask how far can we reproduce the quantitative values given by quantum theory. It will be shown that the psi-epistemic view cannot properly account for the quantitative values, and so must still rely on the same kind of explanations as the "psi-ontic" view.
3D topological lattice models with topologically ordered surface states

Fiona Burnell University of Minnesota

May 07, 2013

PIRSA:13050032

Condensed Matter

I will discuss a family of solvable 3D lattice models that have a ``trivial" bulk, in which all excitations are confined, but exhibit topologically ordered surface states. I will discuss perturbations to these models that can drive a phase transition in which some of these excitations become deconfined, driving the system into a phase with bulk topological order.
Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Cenke Xu University of California, Santa Barbara

May 07, 2013

PIRSA:13050031

High Energy Physics
Majorana Ghosts: From topological superconductor to the origin of neutrino mass, three generations and their mass mixing

Zheng-Cheng Gu Chinese University of Hong Kong

May 07, 2013

PIRSA:13050052

Condensed Matter

The existence of three generations of neutrinos and their mass mixing is a deep mystery of our universe. On the other hand, Majorana's elegant work on the real solution of Dirac equation predicted the existence of Majorana particles in our nature, unfortunately, these Majorana particles have never been observed. In this talk, I will begin with a simple 1D condensed matter model which realizes a T^2=-1 time reversal symmetry protected superconductors and then discuss the physical property of its boundary Majorana zero modes. It is shown that these Majorana zero modes realize a T^4=-1 time reversal doubelets and carry 1/4 spin. Such a simple observation motivates us to revisit the CPT symmetry of those ghost particles--neutrinos by assuming that they are Majorana zero modes. Interestingly, we find that a topological Majorana particle will realize a P^4=-1 parity symmetry as well. It even realizes a nontrivial C^4=-1 charge conjugation symmetry, which is a big surprise from a usual perspective that the charge conjugation symmetry for a Majorana particle is trivial. Indeed, such a C^4=-1 charge conjugation symmetry is a Z_2 gauge symmetry and its spontaneously breaking leads to the origin of neutrino mass. We further attribute the origin of three generations of neutrinos to three distinguishable types of topological Majorana zero modes protected by CPT symmetry. Such an assumption leads to an S3 symmetry in the generation space and uniquely determines the mass mixing matrix with no adjustable parameters! In the absence of CP violation, we derive \theta_12=32degree, \theta_23=45degree and \theta_13=0degree, which is intrinsically closed to the current experimental results. We further predict an exact mass ratio of the three mass eigenstate with m_1/m_3~m_2/m_3=3/\sqrt{5}.

Title	Date	Collection	Type	Info
Quantum Spin Liquids,Density Matrix Renormalization Group, and Entanglement	2013‑05‑09	Emergence & Entanglement II 2013	Conference	View details
Searching for Spin Liquids	2013‑05‑09	Emergence & Entanglement II 2013	Conference	View details
Entangled states of quantum matter	2013‑05‑08	Colloquium	Scientific Series	View details
Holographic insights into quantum critical transport: from branes to Bose-Hubbard	2013‑05‑08	Emergence & Entanglement II 2013	Conference	View details
Quantum renormalization group and AdS/CFT	2013‑05‑08	Emergence & Entanglement II 2013	Conference	View details
Propagation of entanglement in strongly coupled systems from gravity	2013‑05‑08	Emergence & Entanglement II 2013	Conference	View details
Thermodynamical Property of Entanglement Entropy for Excited States	2013‑05‑08	Emergence & Entanglement II 2013	Conference	View details
Impossible symmetry enriched topological phases in 2D and their realization on 3D surface	2013‑05‑07	Emergence & Entanglement II 2013	Conference	View details
Limitations on the psi-epistemic view of quantum states	2013‑05‑07	Quantum Foundations	Scientific Series	View details
3D topological lattice models with topologically ordered surface states	2013‑05‑07	Emergence & Entanglement II 2013	Conference	View details
Field theory, Wave function, and Defects of Symmetry Protected Topological Phases	2013‑05‑07	Emergence & Entanglement II 2013	Conference	View details
Majorana Ghosts: From topological superconductor to the origin of neutrino mass, three generations and their mass mixing	2013‑05‑07	Emergence & Entanglement II 2013	Conference	View details

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Format results

Quantum Spin Liquids,Density Matrix Renormalization Group, and Entanglement

Searching for Spin Liquids

Entangled states of quantum matter

Holographic insights into quantum critical transport: from branes to Bose-Hubbard

Quantum renormalization group and AdS/CFT

Propagation of entanglement in strongly coupled systems from gravity

Thermodynamical Property of Entanglement Entropy for Excited States

Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Limitations on the psi-epistemic view of quantum states

3D topological lattice models with topologically ordered surface states

Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Majorana Ghosts: From topological superconductor to the origin of neutrino mass, three generations and their mass mixing

Quantum Spin Liquids,Density Matrix Renormalization Group, and Entanglement

Searching for Spin Liquids

Entangled states of quantum matter

Holographic insights into quantum critical transport: from branes to Bose-Hubbard

Quantum renormalization group and AdS/CFT

Propagation of entanglement in strongly coupled systems from gravity

Thermodynamical Property of Entanglement Entropy for Excited States

Impossible symmetry enriched topological phases in 2D and their realization on 3D surface

Limitations on the psi-epistemic view of quantum states

3D topological lattice models with topologically ordered surface states

Field theory, Wave function, and Defects of Symmetry Protected Topological Phases

Majorana Ghosts: From topological superconductor to the origin of neutrino mass, three generations and their mass mixing