Transmission of Excitations in a Spin-1 Bose-Einstein Condensate through a Barrier

TL;DR

This study explores how excitations tunnel through a barrier in a spin-1 Bose-Einstein condensate, revealing that most exhibit perfect tunneling at low energies except for a specific massive mode.

Contribution

It provides a detailed analysis of excitation tunneling in spin-1 BECs, highlighting the conditions for anomalous tunneling phenomena and the behavior of different excitation modes.

Findings

Most excitations show perfect tunneling at low momentum.

The quadrupolar spin mode is totally reflected due to its massive spectrum.

Gapless excitations with wave functions similar to the condensate exhibit anomalous tunneling.

Abstract

We investigate tunneling of excitations across a potential barrier separating two spin-1 Bose-Einstein condensates. Using the mean-field theory at the absolute zero temperature, we determine transmission coefficients of excitations in the saturated magnetization state and unsaturated magnetization states. All excitations except the quadrupolar spin mode in the saturated magnetization state show the anomalous tunneling phenomenon characterized as perfect tunneling in the low momentum limit through a potential barrier. The quadrupolar spin mode in the saturated magnetization state, whose spectrum is massive, shows total reflection. We discuss properties common between excitations showing the anomalous tunneling phenomenon. Excitations showing perfect tunneling have gapless spectrum in the absence of the magnetic field, and their wave functions in the low energy limit are the same as the condensate wave function.