Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 8: CE: (General) Theory
TT 8.3: Vortrag
Montag, 22. März 2010, 14:30–14:45, H21
Groundstatable fermionic wavefunctions and their associated many-body Hamiltonians — •Daniel Charrier1 and Claudio Chamon2 — 1Max Planck Institut für Physikkomplexer Systeme, Nöthnitzer Straße38, 01187 Dresden, Germany — 2Physics Department, Boston University, Boston, MA
In the vast majority of many-body problems, it is the kinetic energy part of the Hamiltonian that is best known microscopically, and it is the detailed form of the interactions between the particles, the potential energy term, that is harder to determine from first principles. An example is the case of high temperature superconductors: while a tight-binding model captures the kinetic term, it is not clear that there is superconductivity with only an onsite repulsion and, thus, that the problem is accurately described by the Hubbard model alone. Here we pose the question of whether, once the kinetic energy is fixed, a candidate ground state is groundstatable or not. The easiness to answer this question is strongly related to the presence or the absence of a sign problem in the system. When groundstatability is satisfied, it is simple to obtain the potential energy that will lead to such a ground state. As a concrete case study, we apply these ideas to different fermionic wavefunctions with superconductive or spin-density wave correlations.