Condensed Matter

Detecting Majorana Modes via Non-local Two Particle Interferometry

Pasquale Sodano University of Perugia
February 11, 2011

PIRSA:11020121
Condensed Matter
Simulation of Anyons Using Tensor Network Algorithms

Robert Pfeifer Mosgiel Health Centre
January 28, 2011

PIRSA:11010110
Condensed Matter
Giant flavor-Hall effect and nonlocal transport in Dirac materials

Dmitry Abanin
January 12, 2011

PIRSA:11010085
Condensed Matter
Bringing order through disorder: Localization in the toric code

James Wootton University of Leeds
December 16, 2010

PIRSA:10120043
Condensed Matter
Orthogonality catastrophe 40 years later: fidelity approach, criticality and boundary CFT

Lorenzo Campos Venuti ISI, Turin
December 10, 2010

PIRSA:10120023
Condensed Matter
1-loop diagram in AdS space and the random disorder problem

Yanwen Shang Citigroup Incorporated
November 26, 2010

PIRSA:10110079
Condensed Matter
Holographic Branching and Entanglement Renormalization

Glen Evenbly Georgia Institute of Technology
November 19, 2010

PIRSA:10110076
Condensed Matter
Torsion as a Probe in Condensed Matter Systems

Taylor Hughes University of Illinois Urbana-Champaign
November 12, 2010

PIRSA:10110065
Condensed Matter
Mutual information and the structure of entanglement in quantum field theory

Brian Swingle Brandeis University
October 26, 2010

PIRSA:10100087
Condensed Matter
Quantum Matter

424 talks

Collection Number S021
Talk

Replica topological order in quantum mixed states and quantum error correction

Roger Mong University of Pittsburgh

May 22, 2024

PIRSA:24050089

Condensed Matter

Quantum Spin Liquid Oasis in Desert States of Unfrustrated Spin Models: Mirage ?

Baskaran Ganapathy Institute of Mathematical Sciences

May 21, 2024

PIRSA:24050093

Condensed Matter

The Stability of Gapped Quantum Matter and Error-Correction with Adiabatic Noise - VIRTUAL

Ali Lavasani University of California, Santa Barbara

April 23, 2024

PIRSA:24040113

Condensed Matter

The Ising Model on $S^2$ - The Affine Conjecture

Richard Brower Boston University

April 19, 2024

PIRSA:24040102

Condensed Matter

Efficient Simulation of Quantum Transport in 1D

Frank Pollmann Technical University of Munich (TUM)

April 18, 2024

PIRSA:24040097

Condensed Matter

Observation of Fractional Quantum Anomalous Hall Effect

Xiaodong Xu University of Washington

April 08, 2024

PIRSA:24040085

Condensed Matter

Classification and characterization of interacting crystalline insulators in (2+1)D

Francisco Vladimir Calvera Ciguenas Stanford University

March 19, 2024

PIRSA:24030121

Condensed Matter

Universal theory of strange metals

Subir Sachdev Harvard University

March 14, 2024

PIRSA:24030117

Condensed Matter
See all from this collection

Detecting Majorana Modes via Non-local Two Particle Interferometry

Pasquale Sodano University of Perugia
February 11, 2011

PIRSA:11020121
Condensed Matter
We consider one dimensional devices supporting a pair of Majorana bound states at their ends We firstly show [1] that edge Majorana bound modes allow for processes with an actual transfer of electronic material between well-separated points and provide an explicit computation of the tunnelling amplitude for this process. We then show [2] that these devices can produce remarkable Hanbury-Brown Twiss like interference effects between well separated Dirac fermions of pertinent energies: we find indeed that, at these energies, the simultaneous scattering of two incoming electrons or two incoming holes from the Majorana bound states leads exclusively to an electron-hole final state. This "anti-bunching" in electron-hole internal pseudospin space can be detected through a measure of current-current correlations. Finally, we show [2] that, by scattering appropriate spin polarized electrons from the Majorana bound states, one can engineer a non-local entangler of electronic spins useful for quantum information applications. [1] G. W. Semenoff and P. Sodano: J. Phys. B: At. Mol. Opt. Phys. 40, 1479 (2007); [2] S. Bose and P. Sodano: ÃÂ¢ÃÂÃÂNon-local Handbury- Brown Twiss Interferometry & Entanglement Generation from Majorana
Simulation of Anyons Using Tensor Network Algorithms

Robert Pfeifer Mosgiel Health Centre
January 28, 2011

PIRSA:11010110
Condensed Matter
The simulation of systems of anyons offers a significant challenge to the condensed matter physicist. These systems are presently of substantial theoretical and experimental interest due to their potential for universal quantum computation, but due to their non-trivial exchange statistics, the tools available for their study have been limited. In this talk, I will present a formalism whereby any existing tensor network algorithm may be adapted for use with both Abelian and non-Abelian anyons, culminating in our recent simulations of infinite 1-D chains of interacting anyons using the Multi-scale Entanglement Renormalisation Ansatz, or MERA, demonstrating that tensor network algorithms may be effectively employed in the study of anyonic systems.
Giant flavor-Hall effect and nonlocal transport in Dirac materials

Dmitry Abanin
January 12, 2011

PIRSA:11010085
Condensed Matter
Graphene-like materials provide a unique opportunity to explore quantum-relativistic phenomena in a condensed matter laboratory. Interesting phenomena associated with the internal degrees of freedom, spin and valley, including quantum spin-Hall effect, have been theoretically proposed, but could not be observed so far largely due to disorder and density inhonogeneity. We show that weak magnetic field breaks the symmetries that protect flavor (spin, valley) degeneracy, and induces large bulk non-quantized flavor-Hall effect in graphene. The effect occurs due to flavor splitting which generates the imbalance of the Hall resistivities of the two flavor species. At the Dirac point, flavor-Hall effect is greatly enhanced due to anomalous magnetotransport of Dirac-like carriers. The flavor-Hall effect is robust in the presence of disorder and interactions, and can serve as a hallmark of the quasi-relativistic carriers in the system. It manifests itself in large nonlocal transport mediated by long-lived flavor currents, as well as in flavor injection and accumulation experiments. Recent experimental observation of the giant nonlocal transport in graphene following our prediction opens up new opportunities for creating and manipulating flavor currents. Our work also shows that nonlocal electric transport provides a tool to study neutral modes in solid-states systems.
Bringing order through disorder: Localization in the toric code

James Wootton University of Leeds
December 16, 2010

PIRSA:10120043
Condensed Matter
Anderson localization emerges in quantum systems when randomised parameters cause the exponential suppression of motion. In this talk we will consider the localization phenomenon in the toric code, demonstrating its ability to sustain quantum information in a fault tolerant way. We show that an external magnetic field induces quantum walks of anyons, causing logical information to be destroyed in a time linear with the system size when even a single pair of anyons is present. However, by taking into account the disorder inherent in any physical realisation of the code, it is found that localization allows the memory to be stable in the presence of a finite anyon density. Enhancements to this effect are also considered using random lattices, and similar problems for anyons transported by thermal errors are considered.
Orthogonality catastrophe 40 years later: fidelity approach, criticality and boundary CFT

Lorenzo Campos Venuti ISI, Turin
December 10, 2010

PIRSA:10120023
Condensed Matter
More than forty years ago Nobel laureate P.W. Anderson studied the overlap between two nearby ground states. The result that the overlap tends to zero in the thermodynamics limit was catastrophic for those times. More recently the study of the overlap between ground states, i.e. the fidelity, led to the formulation of the so called fidelity approach to (quantum) phase transition (QPT). This new approach to QPT does not rely on the identification of order parameters or symmetry pattern; rathers it embodies the theory of phase transitions with an operational meaning in terms of measurements. Nowadays orthogonality of ground states is much less surprising. I will provide the general scaling behavior of the fidelity at regular and at critical points of the phase diagrams, Anderson's result being a particular case. These results are useful to many areas of theoretical physics. A related quantity extensively studied here, the fidelity susceptibility, is well known in various other contexts under different names. In metrology it is called quantum Fisher information; in the theory of adiabatic computation it represents the figure of merit for efficient computation; in yet another context it is known as (real part of) the Berry geometric tensor.
1-loop diagram in AdS space and the random disorder problem

Yanwen Shang Citigroup Incorporated
November 26, 2010

PIRSA:10110079
Condensed Matter
AdS/CFT has proven itself a powerful tool in extending our understanding of strongly coupled quantum theories. While studies of AdS/CFT have predominantly focused on tree level calculations, there has been growing interest in the loop effect recently. We studied the 1-loop correction to the gauge boundary-to-boundary correlator due to its coupling to a complex scalar field. In this talk, I would outline our main results, explain the Cutkosky rule in AdS space, and discuss an extra divergence we found in both real and imaginary part of the loop integral. I would then combine our analysis with the replica trick to demonstrate a possible application where one attempts to calculate the DC conductivity in a condensed matter system with random disorder and discuss the limitation and difficulties of our method in its current form.
Holographic Branching and Entanglement Renormalization

Glen Evenbly Georgia Institute of Technology
November 19, 2010

PIRSA:10110076
Condensed Matter
Entanglement renormalization is a coarse-graining transformation for quantum lattice systems. It produces the multi-scale entanglement renormalization ansatz, a tensor network state used to represent ground states of strongly correlated systems in one and two spatial dimensions. In 1D, the MERA is known to reproduce the logarithmic violation of the boundary law for entanglement entropy, S(L)~log L, characteristic of critical ground states. In contrast, in 2D the MERA strictly obeys the entropic boundary law, S(L)~L, characteristic of gapped systems and a class of critical systems. Therefore a number of highly entangled 2D systems, such as free fermions with a 1D Fermi surface, Fermi liquids and spin Bose metals, which display a logarithmic violation of the boundary law, S(L)~L log L, cannot be described by a regular 2D MERA. It is well-known that at low energies, a many-body system may decouple into two or more independent degrees of freedom (e.g. spin-charge separation in 1D systems of electrons). In this talk I will explain how, in systems where low energy decoupling occurs, entanglement renormalization can be used to obtain an explicit decoupled description. The resulting tensor network state, the branching MERA, can reproduce a logarithmic violation of the boundary law in 2D and, as additional numeric evidence also suggests, might be a good ansatz for the highly entangled systems with a 1D Fermi (or Bose) surface mentioned above. In addition, after recalling that the MERA can be regarded as a specific (discrete) realization of the holographic principle, we will see that the branching MERA leads to exotic holographic geometries.
Torsion as a Probe in Condensed Matter Systems

Taylor Hughes University of Illinois Urbana-Champaign
November 12, 2010

PIRSA:10110065
Condensed Matter
: In this talk I will review the common appearance of torsion in solids as well as some new developments. Torsion typically appears in condensed matter physics associated to topological defects known as dislocations. Now we are beginning to uncover new aspects of the coupling of torsion to materials. Recently, a dissipationless viscosity has been studied in the quantum Hall effect. I will connect this viscosity to a 2+1-d torsion Chern-Simons term and discuss possible thought experiments in which this could be measured. Additionally I will discuss a new topological defect in 3+1-d, the torsional monopole, which does not require a lattice deformation to exist. If present, torsional monopoles are likely to impact the behavior of materials with strong spin-orbit coupling such as topological insulators.
Mutual information and the structure of entanglement in quantum field theory

Brian Swingle Brandeis University
October 26, 2010

PIRSA:10100087
Condensed Matter
In this talk I will describe my recent work on the structure of entanglement in field theory from the point of view of mutual information. I will give some basic scaling intuition for the entanglement entropy and then describe how this intuition is better captured by the mutual information. I will also describe a proposal for twist operators that can be used to calculate the mutual information using the replica method. Finally, I will discuss the relevance of my results for holographic duality and entanglement based simulation methods for many body systems.
Quantum Matter

424 talks

Collection Number S021
Talk

Replica topological order in quantum mixed states and quantum error correction

Roger Mong University of Pittsburgh

May 22, 2024

PIRSA:24050089

Condensed Matter

Quantum Spin Liquid Oasis in Desert States of Unfrustrated Spin Models: Mirage ?

Baskaran Ganapathy Institute of Mathematical Sciences

May 21, 2024

PIRSA:24050093

Condensed Matter

The Stability of Gapped Quantum Matter and Error-Correction with Adiabatic Noise - VIRTUAL

Ali Lavasani University of California, Santa Barbara

April 23, 2024

PIRSA:24040113

Condensed Matter

The Ising Model on $S^2$ - The Affine Conjecture

Richard Brower Boston University

April 19, 2024

PIRSA:24040102

Condensed Matter

Efficient Simulation of Quantum Transport in 1D

Frank Pollmann Technical University of Munich (TUM)

April 18, 2024

PIRSA:24040097

Condensed Matter

Observation of Fractional Quantum Anomalous Hall Effect

Xiaodong Xu University of Washington

April 08, 2024

PIRSA:24040085

Condensed Matter

Classification and characterization of interacting crystalline insulators in (2+1)D

Francisco Vladimir Calvera Ciguenas Stanford University

March 19, 2024

PIRSA:24030121

Condensed Matter

Universal theory of strange metals

Subir Sachdev Harvard University

March 14, 2024

PIRSA:24030117

Condensed Matter
See all from this collection

Title	Speaker(s)	Date	Talk Type	Info link
Detecting Majorana Modes via Non-local Two Particle Interferometry	Pasquale Sodano	2011-02-11	Scientific Series	View details
Simulation of Anyons Using Tensor Network Algorithms	Robert Pfeifer	2011-01-28	Scientific Series	View details
Giant flavor-Hall effect and nonlocal transport in Dirac materials	Dmitry Abanin	2011-01-12	Scientific Series	View details
Bringing order through disorder: Localization in the toric code	James Wootton	2010-12-16	Scientific Series	View details
Orthogonality catastrophe 40 years later: fidelity approach, criticality and boundary CFT	Lorenzo Campos Venuti	2010-12-10	Scientific Series	View details
1-loop diagram in AdS space and the random disorder problem	Yanwen Shang	2010-11-26	Scientific Series	View details
Holographic Branching and Entanglement Renormalization	Glen Evenbly	2010-11-19	Scientific Series	View details
Torsion as a Probe in Condensed Matter Systems	Taylor Hughes	2010-11-12	Scientific Series	View details
Mutual information and the structure of entanglement in quantum field theory	Brian Swingle	2010-10-26	Scientific Series	View details
Quantum Matter				View details

Condensed Matter

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