Behavior of heat capacity of an attractive Bose-Einstein Condensate approaching collapse

TL;DR

This paper investigates how the heat capacity of an attractive Bose-Einstein condensate changes as the number of bosons approaches the critical collapse point, revealing non-monotonic behavior near the critical number.

Contribution

It introduces a correlated potential harmonics method to calculate heat capacity of attractive BECs near collapse, incorporating realistic van der Waals interactions.

Findings

Transition temperature increases as N approaches Ncr.

Heat capacity peak initially grows then decreases near Ncr.

Effective potential analysis explains the observed behavior.

Abstract

We report calculation of heat capacity of an attractive Bose-Einstein condensate, with the number N of bosons increasing and eventually approaching the critical number Ncr for collapse, using the correlated potential harmonics (CPH) method. Boson pairs interact via the realistic van der Waals potential. It is found that the transition temperature Tc increases initially slowly, then rapidly as N becomes closer to Ncr . The peak value of heat capacity for a fixed N increases slowly with N, for N far away from Ncr . But after reaching a maximum, it starts decreasing when N approaches Ncr . The effective potential calculated by CPH method provides an insight into this strange behavior.