On-Demand Dissipation in Superconducting Circuits for Error Reduction and Open Systems Studies

Quantum computers could solve important problems in science, engineering, communication, and materials discovery that are beyond the reach of today’s computers. However, current quantum processors still make too many errors for many practical uses. This project addresses one of the central challenges facing quantum processors made using superconducting circuits: how to measure, reset, and protect quantum bits without introducing new errors. The research will develop a new way to remove unwanted energy and noise from quantum circuits only when needed, using a driven “quantum refrigerator” that can cool selected parts of a device on demand. By improving the reliability of quantum measurements and error correction, the project will advance the progress of science and support U.S. leadership in quantum information technology. The project will also train graduate and undergraduate students in quantum hardware, cryogenic measurement, microwave engineering, device simulation, and real-time control, helping build the skilled workforce needed for the growing quantum technology sector. The technical goal of this project is to develop and apply an engineered dissipative circuit, called a "dissipator", in superconducting quantum circuits. The dissipator is a tunable superconducting coupler connected to a high-frequency lossy resonator. When driven parametrically, it induces a resonant exchange interaction with a target qubit or resonator, selectively transferring excitations to the dissipator where they spontaneously decay via the lossy resonator. The project will use this tool to reset transmon qubits with high fidelity, reduce noise in readout resonators from following amplifiers, suppress measurement-induced transitions out of the computational subspace using dissipative quantum Zeno physics, and implement autonomous quantum error correction in qubits encoded in high-dimensional spaces. The project will also use the same platform to study fundamental short-time dynamics of dissipation and the emergence of irreversible energy decay from underlying quantum evolution. The expected outcomes include improved methods for fast reset, high-fidelity mid-circuit measurement, reduced hardware overhead for scalable readout, and new experimental understanding of dissipation as both an error source and a resource for quantum information processing. 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. NSF Award ID: 2609794 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Eli Levenson-Falk | Institution: University of Southern California, LOS ANGELES, CA | Award Amount: $462,223 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2609794 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2609794.html