Persistent Supercurrent Atom Chip

TL;DR

This paper demonstrates trapping rubidium 87 atoms using a persistent supercurrent in a superconducting MgB2 loop circuit on a sapphire surface, with an on-chip thermal switch for supercurrent control.

Contribution

It introduces a novel method of trapping atoms with a supercurrent in a superconducting circuit and develops an on-chip thermal switch for precise supercurrent control.

Findings

Successful trapping of rubidium atoms using supercurrent-generated potentials

Development of a thermal switch to control supercurrent on-chip

Ability to set supercurrent without external sources

Abstract

Rubidium 87 atoms are trapped in an Ioffe-Pritchard potential generated with a persistent supercurrent that flows in a loop circuit patterned on a sapphire surface. The superconducting circuit is a closed loop made of 100 micro meter wide MBE-grown MgB2 stripe carrying a supercurrent of 2.5 A. To control the supercurrent in the stripe, an on-chip thermal switch operated by a focused argon-ion laser is developed. The switch operates as an on/off switch of the supercurrent, or as a device to set the current to a specific value with the aid of an external magnetic field. The current can be set even without an external source if the change is in decreasing direction.