Quantum Optical Implementation of Quantum Information Processing and Classical Simulation of Many-Body Physics from Quantum Information Perspective.

Quantum Information;Cavity QED;Hubbard Model;Classical Simulation;Quantum Many-body Physics;Physics;Science;Physics

Wang, BinSteel, Duncan G. ;

University of Michigan

关键词: Quantum Information;    Cavity QED;    Hubbard Model;    Classical Simulation;    Quantum Many-body Physics;    Physics;    Science;    Physics;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/61688/binwz_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This thesis is composed of two parts. In the first part we summarize our studyon implementation of quantum information processing (QIP) in optical cavity QEDsystems, while in the second part we present our numerical investigations on stronglyinteracting Fermi systems using a powerful numerical algorithm developed from theperspective of quantum information theory.We explore various possible applications of cavity QED in the strong couplingregime to quantum information processing tasks theoretically, including efficientpreparation of Schrodinger-cat states for traveling photon pulses, robust implemen-tation of conditional quantum gates on neutral atoms, as well as implementation ofa hybrid controlled SWAP gate. We analyze the feasibility and performance of ourschemes by solving corresponding physical models either numerically or analytically.We implement a novel numerical algorithm called Time Evolving Block Decimation (TEBD), which was proposed by Vidal from the perspective of quantuminformation science. With this algorithm, we numerically study the ground stateproperties of strongly interacting fermions in an anisotropic optical lattice acrossa wide Feshbach resonance. The interactions in this system can be described by ageneral Hubbard model with particle assisted tunneling. For systems with equal spinpopulation, we find that the Luther-Emery phase, which has been known to existonly for attractive on-site interactions in the conventional Hubbard model, could alsobe found even in the case with repulsive on-site interactions in the general Hubbardmodel. Using the TEBD algorithm, we also study the effect of particle assisted tun-neling in spin-polarized systems. Fermi systems with unequal spin population andattractive interaction could allow the existence of exotic superfluidity, such as theFulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. In the general Hubbard model, suchexotic FFLO pairing of fermions could be suppressed by high particle assisted tunneling rates. However, at low particle assisted tunneling rates, the FFLO order couldbe enhanced. The effect of particle density inhomogeneity due to the presence of aharmonic trap potential is also discussed based on the local density approximation.