NSF Award
2231356
Non-technical Description:<br/>An important problem in scalable quantum computing is to locally address qubits in an energy-efficient manner. Current approaches, for example, use microwaves at different frequencies conveyed through waveguides to address different qubits that are resonant to different frequencies. Such microwave fields consume significant energy and their confinement to the nanometer scale is challenging. This project will use voltage-control of nanoscale magnets for energy efficient and selective addressing of spin qubits with high spatial resolution and will be easy to integrate with existing foundry manufacturing processes. Thus, this project will synergistically bring together the fields of spintronics and quantum computing. The project team will create a vibrant Quantum Information Science and Engineering (QISE) program at Virginia Commonwealth University (VCU) and integrate this research with teaching and outreach to educate students in QISE at the graduate, undergraduate, and K-12 levels while leveraging existing QISE expertise at the University of California, Los Angeles (UCLA) through collaboration. Such activities include developing a new QISE course, lab modules, and K-12 outreach through workshops and summer internships for underrepresented students in QISE. <br/><br/>Technical Description:<br/>This project will simulate and demonstrate highly localized control of qubits using nanomagnets driven by an electric field at the Larmor frequency of proximally located spin qubits to implement single-qubit quantum gates with state-of-the-art fidelities and high energy efficiency. Towards realizing the above research vision, the project will (1) simulate and experimentally demonstrate voltage control of nanoscale magnets using heterostructures to generate the desired magnetic field pulses locally in a confined nanoscale volume for high fidelity single spin qubit gates, (2) demonstrate that the voltage-controlled magnetization dynamics of such nanomagnets can control NV spin qubit centers in diamond with high fidelity that can be read optically, and (3) simulate the collective dynamics of mesoscopic spin ensembles comprising 10-100 spins (for an increased signal to noise ratio and possibly error correction through spin interaction to reduce dephasing) and demonstrate that voltage-controlled nanomagnets can control such an ensemble of spins with high fidelity.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
