Principles of an atomtronic transistor

TL;DR

This paper explores how ultracold atoms in a triple-well potential can mimic transistor behavior, demonstrating gain, negative resistance, and controllable chemical potentials and temperatures using a semiclassical model.

Contribution

It introduces a novel atomtronic transistor model using a semiclassical approach, showing transistor-like behavior with gain and negative resistance in ultracold atom systems.

Findings

Gate chemical potential can exceed source potential.

Device exhibits negative resistance and transresistance regimes.

Current gain can be greater than unity.

Abstract

A semiclassical formalism is used to investigate the transistor-like behavior of ultracold atoms in a triple-well potential. Atom current flows from the source well, held at fixed chemical potential and temperature, into an empty drain well. In steady-state, the gate well located between the source and drain is shown to acquire a well-defined chemical potential and temperature, which are controlled by the relative height of the barriers separating the three wells. It is shown that the gate chemical potential can exceed that of the source and have a lower temperature. In electronics terminology, the source-gate junction can be reverse-biased. As a result, the device exhibits regimes of negative resistance and transresistance, indicating the presence of gain. Given an external current input to the gate, transistor-like behavior is characterized both in terms of the current gain, which can be greater than unity, and the power output of the device.