An ultra-stable 1.5 T permanent magnet assembly for qubit experiments at cryogenic temperatures

Abstract

Magnetic fields are a standard tool in the toolbox of every physicist and are required for the characterization of materials, as well as the polarization of spins in nuclear magnetic resonance or electron paramagnetic resonance experiments. Quite often, a static magnetic field of sufficiently large, but fixed, magnitude is suitable for these tasks. Here, we present a permanent magnet assembly that can achieve magnetic field strengths of up to 1.5 T over an air gap length of 7 mm. The assembly is based on a Halbach array of neodymium magnets, with the inclusion of the soft magnetic material Supermendur to boost the magnetic field strength inside the air gap. We present the design, simulation, and characterization of the permanent magnet assembly, measuring an outstanding magnetic field stability with a drift rate of |D| < 2.8 ppb/h. Our measurements demonstrate that this assembly can be used for spin qubit experiments inside a dilution refrigerator, successfully replacing the more expensive and bulky superconducting solenoids.

Document Details

Document Type
Pub Defense Publication
Publication Date
Aug 01, 2021
Source ID
10.1063/5.0055318

Entities

People

  • Andrea Morello
  • Arne Laucht
  • Chris Adambukulam
  • H. G. Stemp
  • Mateusz T MÄ…dzik
  • Serwan Asaad
  • Vikas K. Sewani

Organizations

  • Army Research Office
  • Australian Research Council
  • University of New South Wales

Tags

Fields of Study

  • Physics

Readers

  • Electrical Engineering
  • Materials Science and Engineering.
  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.

Technology Areas

  • Microelectronics
  • Microelectronics - Microelectromechanical Systems
  • Quantum Science - Quantum Dots