Innovative material offers new approach to quantum memory

Innovative material offers new approach to quantum memory
by Clarence Oxford
Los Angeles CA (SPX) Apr 08, 2024

A recent discovery by physicists at Rice University has introduced a new quantum material that shows promise for developing memory systems akin to flash storage but for quantum bits, or qubits, essential for quantum computing.

Traditional phase-changing materials have been foundational in non-volatile memory storage, such as rewritable DVDs. In these systems, a laser alters the material's structure, allowing it to switch between crystalline and amorphous states-distinct forms that represent binary data. Inspired by this technology, the Rice team, led by physicist Ming Yi, explored similar concepts within quantum materials.

Published in Nature Communications, their research detailed how an alloy of iron, germanium, and tellurium could toggle between two electronic phases through heating. This method manipulates electron paths in the material, stabilizing them into topologically protected states, a critical feature for reliable quantum computing. Such states reduce decoherence, a major hurdle where qubits lose their quantum properties.

"The discovery was serendipitous," explained Yi. Initially drawn to the material for its magnetic characteristics, the team observed unexpected phase changes during their tests. Over two years, through collaborative efforts with multiple institutions, it became clear that these phases were influenced by the rate at which the material cooled following heating.

This iron-germanium-tellurium alloy, however, does not require melting and re-solidifying to change states, unlike typical phase-change memory technologies. Instead, vacancies within the crystal lattice-empty spaces left by atoms-rearrange themselves into new patterns with varying cooling durations. Adjusting these vacancy patterns effectively switches the material's phase without needing extreme temperatures.

Yi emphasized the novelty of this approach: "Adjusting vacancy order to control material properties offers a new lens to examine quantum materials beyond traditional stoichiometric methods, where elements are in fixed ratios." This research suggests vacancy manipulation could similarly influence other materials, potentially broadening the scope of quantum material applications.

Rice theoretical physicist Qimiao Si, also a study co-author, highlighted the practical implications of this discovery. "It's fascinating to see how a small adjustment in the crystal structure can lead to significant changes in material behavior. This ability to 'tune' material properties on demand adds an exciting dimension to our theoretical understanding and opens new avenues for material design."

The implications of such a discovery are vast. Quantum computers rely on qubits for operations far exceeding the capability of classical bits. However, their practical use has been limited by qubit instability and susceptibility to error. Implementing a stable, reversible memory that retains qubit information even when the system is off could dramatically enhance quantum computing's feasibility and efficiency.

This advancement in quantum material science not only paves the way for more stable quantum computing but also invites further exploration into how changing vacancy orders can affect other materials. As quantum technology continues to evolve, discoveries like this underscore the potential for significant technological leaps in data storage and processing.

Research Report:Reversible non-volatile electronic switching in a near-room-temperature van der Waals ferromagnet