Title




Boson and fermion manybody assemblies: fingerprints of excitations in the groundstate wave functions, with examples of superfluid and the homogeneous correlated electron liquid
 
Author




 
Abstract




After a brief summary of some basic properties of ideal gases of bosons and of fermions, two manybody Hamiltonians are cited for which groundstate wave functions allow the generation of excited states. Because of the complexity of groundstate manybody wave functions, we then consider properties of reduced density matrices, and in particular, the diagonal element of the secondorder density matrix. For both the homogeneous correlated electron liquid and for an assembly of charged bosons, the groundstate pair correlation function g(r) has fingerprints of the zeropoint energy of the plasmon modes. These affect crucially the static structure factor, S(k), in the long wavelength limit. This is best understood by means of the OrnsteinZernike direct correlation function c(r), which plays an important role throughout this article. Turning from such charged liquids, both boson and fermion, to superfluid 4He, the elevated temperature (T) structure factor S(k, T) is related, albeit approximately, to its zerotemperature counterpart, via the velocity of sound, reflecting the collective phonon excitations and the superfluid density. Finally, some future directions are pointed. 
 
Language




English
 
Source (journal)




Physics and chemistry of liquids.  London
 
Publication




London
:
2008
 
ISSN




00319104
 
DOI




10.1080/00319100802239503
 
Volume/pages




46
:5
(2008)
, p. 465480
 
ISI




000260382800001
 
Full text (Publisher's DOI)




 
