Nonperturbative calculation of the London-van der Waals interaction potential

作者：Berman P R^*; Ford G W; Milonni P W

来源：Physical Review A, 2014, 89(2): 022127.

DOI：10.1103/PhysRevA.89.022127

The so-called remarkable formula [G. W. Ford, J. T. Lewis, and R. F. O'Connell, Phys. Rev. Lett. 55, 2273 (1985)] for the Helmholtz free energy is applied to the problem of determining the interaction potential to all orders in the coupling strength of a pair of oscillator dipoles interacting through the familiar dipole-dipole interaction of electrodynamics. Simple, straightforward calculations lead to expressions for (1) the London short-range potential, (2) the Casimir-Polder long-range potential, and (3) the potential at high temperature. Explicit results are shown for both the temperature dependence of the interaction potential and its deviation from the weak-coupling limit. It is stressed that the interaction potential is a change in free energy, not the energy; in particular, in the high temperature case, the change of energy is zero.

• 出版日期2014-2-28