Theory Seminars

Fermion production in gauge theories

Speaker: 
Florian Hebenstreit (University of Heidelberg)
Event Date and Time: 
Mon, 2013-11-18 12:00 - 13:00
Location: 
Hennings 318
Fermion production in gauge theories Abstract: We investigate the production of fermions by strong background fields in Abelian gauge theories ('Schwinger effect'). We compute the non-equilibrium time evolution of gauge-invariant observables and investigate the decay of the field due to the backreaction mechanism. We discuss distinctive features of the momentum spectrum of created particles (3+1 dimensional QED) and establish a two-stage process in the dynamics of string breaking (1+1 dimensional QED).

Generation and propagation of correlations in non-equilibrium many-body systems

Speaker: 
Dr. Jean-Sebastien Bernier (UBC)
Event Date and Time: 
Mon, 2013-11-25 12:00 - 13:00
Location: 
Room 318 Hennings
Abstract: Recent advances in the development of fast probing and control techniques applicable to correlated systems have opened up the possibility to dynamically prepare complex quantum many-body states. Experimentally, effective phase transitions have been induced through the application of external driving fields, and states have been realized using tailored environments. On the theoretical side, despite tremendous progress in recent years, many of the basic concepts behind the dynamical generation of states still remain to be understood.

CORRELATED WORLDLINE THEORY and GRAVITATIONAL DECOHERENCE in SOLID STATE SYSTEMS

Speaker: 
Prof. Phil Stamp (UBC)
Event Date and Time: 
Mon, 2013-12-02 12:00 - 13:00
Location: 
Room 318 Hennings
There are fundamental differences between (i) gravity and (ii) quantum mechanics/quantum field theory, which have blocked all attempts to find an experimentally testable theory of quantum gravity. Here I describe a theory (the correlated worldline theory) in which correlations between paths in a path integral, mediated by gravity, cause a gradual breakdown of the superposition principle, and lead to testable consequences for experiments in condensed matter systems (notably in optomechanical systems).

Exact Holographic Mapping and Emergent Space-time Geometry

Speaker: 
Prof. Xiaoliang Qi (Stanford University)
Event Date and Time: 
Mon, 2013-11-04 12:00 - 13:00
Location: 
Henning 318
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate
Abstract: Holographic duality is a duality between quantum many-body systems (boundary) and gravity systems with one additional spatial dimension (bulk). In this talk, I will describe a new approach to holographic duality for lattice systems, called the exact holographic mapping. The key idea of this approach can be summarized by two points: 1) The bulk theory is nothing but the boundary theory viewed in a different basis. 2) Space-time geometry is determined by the structure of correlations and quantum entanglement in a quantum state.

A symmetry-respecting topologically-ordered surface phase of 3d electron topological insulators.

Speaker: 
Dr. Max Metliski (UCSB)
Event Date and Time: 
Mon, 2013-10-28 12:00 - 13:00
Location: 
Hennings 318
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate
A 3d electron topological insulator (ETI) is a phase of matter protected by particle-number conservation and time-reversal symmetry. It was previously believed that the surface of an ETI must be gapless unless one of these symmetries is broken. A well-known symmetry-preserving, gapless surface termination of an ETI supports an odd number of Dirac cones. In this talk, I will show that in the presence of strong interactions, an ETI surface can actually be gapped and symmetry preserving, at the cost of carrying an intrinsic two-dimensional topological order.

THIS SEMINAR HAS BEEN CANCELLED.

Event Date and Time: 
Mon, 2013-10-21 12:00 - 13:00
Location: 
Hennings 318
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate

Gravitational dynamics from entanglement "Thermodynamics"

Speaker: 
Prof. Mark Van Raamsdonk (UBC)
Event Date and Time: 
Mon, 2013-10-07 12:00 - 13:00
Location: 
Hennings 318
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate
AdS/CFT appears to provide a definition of certain theories of quantum gravity based on ordinary quantum field theories. A significant open question is how and why spacetime / gravity emerge from the CFT physics. In this talk, I will discuss recent work suggesting that spacetime emerges due to the entanglement of degrees of freedom in the CFT.

Understanding mechanical properties of disordered solids: how computers can help (note special start time)

Speaker: 
Prof. Jean-Louis Barrat (University of Joseph Fourier, Grenoble France)
Event Date and Time: 
Mon, 2013-09-30 11:00 - 12:00
Location: 
Hennings 318 (***** Note this seminar starts at 11am *****)
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate

Imbalanced Fermi gases in two dimensions

Speaker: 
Prof. Dan Sheehy (Louisiana State University)
Event Date and Time: 
Mon, 2013-09-23 12:00 - 13:00
Location: 
Hennings 318
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate
Trapped fermionic atomic gases exhibit superfluid states, akin to superconductivity in a metal, due to the pairing of two species of atomic fermion.

Topological Superconductor-Luttinger Liquid Junctions

Speaker: 
Ian Affleck
Event Date and Time: 
Mon, 2013-09-16 12:00 - 13:00
Location: 
Hennings 318
Local Contact: 
Fei Zhou
Intended Audience: 
Graduate
Syndicate content
Website development by Checkmark Media. Designed by Armada.

a place of mind, The University of British Columbia

Faculty of Science
Department of Physics and Astronomy
6224 Agricultural Road
Vancouver, BC V6T 1Z1
Tel 604.822.3853
Fax 604.822.5324

Emergency Procedures | Accessibility | Contact UBC | © Copyright The University of British Columbia