Coupling Magnetism and Microwaves To Clamp Down on Noise in Quantum Information

(SciTechDaily) The U.S. Department of Energy (DOE) has recently funded both DOE’s Argonne National Laboratory and the University of Illinois Champaign-Urbana (UIUC) in a new project that will explore coupling magnetism and microwaves for quantum discoveries.
In the emerging field of quantum information science, microwaves may play a fundamental role because their physical properties enable them to provide desired quantum functionality at temperatures near to absolute zero (minus 460 degrees Fahrenheit) — a necessity because heat creates errors in quantum operations. However, microwaves are susceptible to noise, which is unwanted energy that disturbs signal and data transmission.
The research team will be exploring whether magnons could partner with microwave photons to ensure that microwaves can only travel in one direction, thereby essentially eliminating noise. Magnons are the fundamental excitations of magnets. By contrast, microwave photons result from electronic excitations producing waves like those in a microwave oven.
The Argonne scientists will build upon their earlier efforts to create a superconducting circuit integrated with magnetic elements. The magnons and photons talk to each other through this superconducting device. Superconductivity — the complete absence of electrical resistance — allows coupling of magnons and microwave photons at near to absolute zero.
The UIUC researchers will be searching for magnets that work at ultracold temperatures. They will be testing known and new material systems to find candidates that can handle an ultracold environment and operate in a real quantum device.
“If we are successful within these three years, we will have magnetic structures directly integrated with quantum circuitry,” Hoffmann said. “This work could also apply to non-quantum devices for sensing and communication, such as in Wi-Fi or Bluetooth technologies.”