Scientists at Argonne National Laboratory and the University of Chicago have developed an advanced computer modeling method that accurately predicts and fine-tunes key magnetic properties of molecular qubits, a crucial step toward designing more efficient quantum devices.
Qubits, the fundamental units of quantum information, are essential for the development of next-generation quantum computers and sensors. The research team focused on molecular qubits based on chromium centers within crystals. Using comprehensive simulations, they identified how specific factors in the host material influence the tunability of the qubit’s magnetic properties, particularly zero-field splitting (ZFS), which describes the splitting of an atom’s spin into different magnetic energy levels without any external electromagnetic field.
The study demonstrated how manipulating the geometry of the crystal environment and the electric fields generated by the crystal’s chemical composition can control the ZFS. These findings allow for the prediction of qubit coherence times, indicating how long a qubit can reliably process information before degrading. The model’s predictions showed strong agreement with experimental results.
Led by Professor Giulia Galli, who holds positions at both Argonne and the University of Chicago’s Pritzker School of Molecular Engineering and Department of Chemistry, the team emphasized that such computational tools provide new design principles for engineering qubits tailored to specific quantum applications, including quantum communication, sensing, and computing.
The work, published in the Journal of the American Chemical Society and supported by the Department of Energy’s Q-NEXT National Quantum Information Science Research Center, marks the first computational method to both accurately predict ZFS in chromium molecular qubits and identify the role of the host environment’s electric fields in tuning these properties.
This advancement is expected to enhance the ability to design molecular qubits with desired characteristics, potentially accelerating the development of reliable quantum technologies.