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报告内容
摘 要
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We study
a two-dimensional spin-polarized Fermi gas with electric dipoles aligned by
an external electric field. This system is known to exhibit three stable
phases, namely the normal Fermi liquid, the p-wave superfluid and the density
wave phase (stripe phase). Our study focus on two aspects of the phase
diagram. First we investigate the possibility of a new zero-temperature phase
in which the density wave order and the superfluid order coexist. We find
that the system in the density wave phase eventually becomes unstable towards
pairing as the tilting angle of the dipoles increases and the dipolar
interaction becomes more attractive. Importantly,the resulting superfluid
order does not destroy the density wave order, making the system a type of
supersolid. We discuss possible experimental methods by which such a phase
can be detected. The second part of our study concerns the finite temperature
phase transition of the stripe phase. This phase can be viewed as the quantum
analogue of the classical liquid crystal phase found in electronic materials.
We base our analysis on the elastic energy of the system, in which the
stiffness constants are determined using the self-consistent Hartree-Fock
theory. The melting of this phase is driven by the proliferation of
topological defects called dislocations via the so-called
Berezinskii-Kosterlitz-Thouless (BKT) mechanism. We calculate the BKT
critical temperature by the well-known renormalisation group equations.
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报告人
简 介
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Education:
Ph.D. Physics,
Queen’s University, Canada, 2009 - 2013.
M.S. Physics,
Peking University, China, 2005-2007.
B.S. Physics,
Wuhan University, China, 2000-2004.
Employment:
Postdoctoral
fellow, Aarhus University, Denmark, Since May 2014
Postdoctoral
fellow, Queen’s University, Canada, May 2013 - April 2014
Research and
teaching assistant, Queen’s University, Canada, Feb. 2009-April 2013
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