Optical lattice quantum simulator for quantum electrodynamics in strong external fields: spontaneous pair creation and the SauterSchwinger effect
Abstract
The spontaneous creation of electronpositron pairs out of the vacuum due to a strong electric field is a spectacular manifestation of the relativistic energymomentum relation for the Dirac fermions. This fundamental prediction of quantum electrodynamics has not yet been confirmed experimentally, as the generation of a sufficiently strong electric field extending over a large enough spacetime volume still presents a challenge. Surprisingly, distant areas of physics may help us to circumvent this difficulty. In condensed matter and solid state physics (areas commonly considered as lowenergy physics), one usually deals with quasiparticles instead of real electrons and positrons. Since their mass gap can often be freely tuned, it is much easier to create these light quasiparticles by an analogue of the SauterSchwinger effect. This motivates our proposal for a quantum simulator in which excitations of ultracold atoms moving in a bichromatic optical lattice represent particles and antiparticles (holes) satisfying a discretized version of the Dirac equation together with fermionic anticommutation relations. Using the language of second quantization, we are able to construct an analogue of the spontaneous pair creation which can be realized in an (almost) tabletop experiment.
 Publication:

New Journal of Physics
 Pub Date:
 March 2012
 DOI:
 10.1088/13672630/14/3/035001
 arXiv:
 arXiv:1109.2426
 Bibcode:
 2012NJPh...14c5001S
 Keywords:

 Quantum Physics;
 Condensed Matter  Quantum Gases
 EPrint:
 21 pages, 10 figures