Abstract
We present a method by which a quantum-mechanical partition function can be approximated from below by an effective classical partition function. The associated potential is obtained by a simple smearing procedure. For a strongly anharmonic oscillator and a double-well potential, the lowest approximation gives a free energy which is accurate to a few percent, even at zero temperature.
- Received 20 May 1986
DOI:https://doi.org/10.1103/PhysRevA.34.5080
©1986 American Physical Society