Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover Export

@misc{citeulike:2570679, abstract = {We determine the effects of quantum fluctuations about the T=0 mean field solution of the BCS-BEC crossover in a dilute Fermi gas using the functional integral method. These fluctuations are described in terms of the zero point motion of collective modes and the virtual scattering of gapped quasiparticles. We calculate their effects on various measurable properties, including chemical potential, ground state energy, the gap, the speed of sound and the Landau critical velocity. At unitarity, we find excellent agreement with quantum Monte Carlo and experimental results. In the BCS limit, we show analytically that we obtain Fermi liquid interaction corrections to thermodynamics including the Hartree shift. In the BEC limit, we show that the theory leads to an approximate description of the reduction of the scattering length for bosonic molecules and also obtain quantum depletion of the Lee-Yang form. At the end of the paper, we describe a method to include feedback of quantum fluctuations into the gap equation, and discuss the problems of self-consistent calculations in satisfying Goldstone's theorem and obtaining ultraviolet finite results at unitarity.}, archivePrefix = {arXiv}, author = {Diener, Roberto B. and Sensarma, Rajdeep and Randeria, Mohit}, citeulike-article-id = {2570679}, citeulike-linkout-0 = {http://arxiv.org/abs/0709.2653}, citeulike-linkout-1 = {http://arxiv.org/pdf/0709.2653}, day = {17}, eprint = {0709.2653}, keywords = {bcs, bec, fermi\_gas}, month = {Sep}, posted-at = {2008-03-21 21:36:27}, priority = {2}, title = {Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover}, url = {http://arxiv.org/abs/0709.2653}, year = {2007} }

TY - ELEC ID - citeulike:2570679 L3 - citeulike-article-id:2570679 N2 - We determine the effects of quantum fluctuations about the T=0 mean field solution of the BCS-BEC crossover in a dilute Fermi gas using the functional integral method. These fluctuations are described in terms of the zero point motion of collective modes and the virtual scattering of gapped quasiparticles. We calculate their effects on various measurable properties, including chemical potential, ground state energy, the gap, the speed of sound and the Landau critical velocity. At unitarity, we find excellent agreement with quantum Monte Carlo and experimental results. In the BCS limit, we show analytically that we obtain Fermi liquid interaction corrections to thermodynamics including the Hartree shift. In the BEC limit, we show that the theory leads to an approximate description of the reduction of the scattering length for bosonic molecules and also obtain quantum depletion of the Lee-Yang form. At the end of the paper, we describe a method to include feedback of quantum fluctuations into the gap equation, and discuss the problems of self-consistent calculations in satisfying Goldstone's theorem and obtaining ultraviolet finite results at unitarity. TI - Quantum Fluctuations in the Superfluid State of the BCS-BEC Crossover KW - bcs KW - bec KW - fermi_gas AU - Diener, Roberto AU - Sensarma, Rajdeep AU - Randeria, Mohit PY - 2007/Sep/17/ UR - http://arxiv.org/abs/0709.2653 ER -