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arXiv · 1110.6348

Adiabatic continuity and broken symmetry in many-electron systems: a variational perspective

Dionys Baeriswyl
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Abstract

Variational wave functions are very useful for describing the panoply of ground states found in interacting many-electron systems. Some particular trial states are "adiabatically" linked to a reference state, from which they borrow the essential properties. A prominent example is the Gutzwiller ansatz, where one starts with the filled Fermi sea. A simple soluble example, the anisotropic XY chain, illustrates the adiabatic continuity of this class of wave functions. To describe symmetry breaking, one has to modify the reference state accordingly. Alternatively, a quantum phase transition can be described by a pair of variational wave functions, starting at weak and strong coupling, respectively.

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Dionys Baeriswyl. 2011-10-28. Adiabatic continuity and broken symmetry in many-electron systems: a variational perspective. https://doi.org/10.1002/andp.201100044

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