Scientists at Argonne National Laboratory and the University of Chicago have developed an advanced computer modeling method to predict and engineer key magnetic properties of molecular qubits, a critical step toward more reliable quantum technologies.
A qubit, the fundamental unit of quantum information processing, is essential for building next-generation quantum computers and sensors. The new approach accurately forecasts the zero-field splitting (ZFS)—the magnetic energy level differences within molecular qubits—and identifies how factors such as the geometry and electric fields of the host crystal influence these properties. These predictions align closely with experimental observations.
Led by University of Chicago Professor Giulia Galli, who is also a senior scientist at Argonne and holds professorships in molecular engineering and chemistry at UChicago, the research focused on chromium-based molecular qubits. Molecular qubits consist of molecules embedded within crystals and use the quantum property of atomic spin to encode information. The ability to control the ZFS is vital for tuning qubit behavior, minimizing interference in multi-qubit systems, and extending coherence times, which determine how long a qubit can maintain information.
Argonne postdoctoral researcher Michael Toriyama emphasized the design potential of the computational method, noting it provides guiding principles for engineering qubits tailored to specific applications such as quantum communication, sensing, or computing. The method models how design changes in the qubit’s surrounding environment can alter its magnetic properties, allowing for precise adjustments without costly trial and error.
Graduate student Lorenzo Baldinelli, the paper’s first author, highlighted that the study is the first to link ZFS control to the manipulation of electric fields from the crystal environment, thereby extending predictive capability beyond the qubit itself to its surroundings. The team credited their success to a multidisciplinary collaboration, combining chemistry, materials science, and physics expertise, and leveraging years of methodological development within Galli’s group.
The findings, published in the Journal of the American Chemical Society, were supported by Q-NEXT, a Department of Energy National Quantum Information Science Research Center led by Argonne. The breakthrough lays foundational work for designing molecular qubits with specifications that could accelerate the development of future quantum devices.