Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Non-Gaussian Variational Approach to Fermi Polarons in One- and
  Two-dimensional Lattices   We study the Fermi polaron problem of one mobile spin-up impurity immersed
atop the bath consisting of spin-down fermions in one- and two-dimensional
square lattices. We solve this problem by applying a variational approach with
non-Gaussian states after separating the impurity and the background by the
Lee-Low-Pines transformation. The ground state for a fixed total momentum can
be obtained via imaginary time evolution for the variational parameters. For
the one-dimensional case, the variational results are compared with numerical
solutions of the matrix product state method with excellent agreement. In
two-dimensional lattices, we focus on the dilute limit, and find a
polaron--molecule evolution in consistence with previous results obtained by
variational and quantum Monte Carlo methods for models in continuum space.
Comparing to previous works, our method provides the lowest ground state energy
in the entire parameter region considered, and has an apparent advantage as it
does not need to assume {\it in priori} any specific form of the variational
wave function.

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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat
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The categories of this paper are: cs
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The categories of this paper are: physics
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci