Decreasing critical temperature of gas BEC in spatially periodic potential and relevance to experiments treated by Mott-Hubbard model

TL;DR

This paper demonstrates that increasing the depth of a periodic potential lowers the critical temperature for Bose-Einstein condensation in gases, providing a new physical explanation and linking it to experimental observations in optical lattices.

Contribution

It introduces an alternative theoretical approach explaining the decrease in critical temperature with potential depth, connecting it to quantum recoil energy and experimental Mott-Hubbard phenomena.

Findings

Critical temperature decreases with deeper periodic potentials.

Quantum recoil energy determines the scale of temperature decay.

The theory aligns with experimental results on BEC in optical lattices.

Abstract

It is shown that the critical temperature of gas Bose-Einstein condensation decreases in deepening periodic potential, in contrast to common regularity in a separate potential well. The physical explanation of this phenomenon is given. Characteristic scale of potential energies decaying the critical temperature is the quantum recoil energy of periodic potential. The theory represents an alternative and direct approach to the experimental results (C.Orzel et al Science 291, 2386 (2001); M.Greiner et al, Nature 415, 39 (2002)) obtained with BEC in optical lattices and treated as the phase squeezing or Mott transition processes.