scholarly journals Mean‐Field and Classical Limit for the N ‐Body Quantum Dynamics with Coulomb Interaction

Author(s):  
François Golse ◽  
Thierry Paul
2001 ◽  
Vol 15 (08) ◽  
pp. 1117-1126 ◽  
Author(s):  
JUNGHOON HAN ◽  
QIANG-HUA WANG ◽  
DUNG-HAI LEE

We study mean-field phases of the t–J model with long-range Coulomb interaction. In the order of increasing doping density we find a classical antiferromagnet, charge and spin stripes, and a uniform d-wave superconductor, at the realistic doping parameters. Both in-phase and anti-phase stripes exist as metastable configurations, but the in-phase stripes have a slightly lower energy. The dependence of the stripe width and the inter-stripe spacing on the doping is examined. Effects of fluctuations around the mean-field states are discussed.


2003 ◽  
Vol 13 (01) ◽  
pp. 59-73 ◽  
Author(s):  
S. GRAFFI ◽  
A. MARTINEZ ◽  
M. PULVIRENTI

We prove that, for a smooth two-body potential, the quantum mean-field approximation to the nonlinear Schrödinger equation of the Hartree type is stable at the classical limit h → 0, yielding the classical Vlasov equation.


1999 ◽  
Vol 54 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Michael Fleischhauer ◽  
Oliver Veits

Abstract We analyze the long-time quantum dynamics of degenerate parametric down-conversion from an initial sub-harmonic vacuum (spontaenous down-conversion). Standard linearization of the Heisenberg equations of motion fails in this case, since it is based on an expansion around an unstable classical solution and neglects pump depletion. Introducing a mean-field approximation we find a periodic exchange of energy between the pump and subharmonic mode goverened by an anharmonic pendulum equation. From this equation the optimum interaction time or crystal length for maximum conversion can be determined. A numerical integration of the 2-mode Schrödinger equation using a dynamically optimized basis of displaced and squeezed number states verifies the characteristic times predicted by the mean-field approximation. In contrast to semiclassical and mean-field predictions it is found that quantum fluctuations of the pump mode lead to a substantial limitation of the efficiency of parametric down-conversion.


Author(s):  
Luis B. Castro ◽  
Luiz P. de Oliveira ◽  
Marcelo G. Garcia ◽  
Antonio S. de Castro

Pramana ◽  
1991 ◽  
Vol 36 (3) ◽  
pp. 271-288
Author(s):  
Swagata Nandi ◽  
C S Shastry

Sign in / Sign up

Export Citation Format

Share Document