Phys.org August 15, 2024
As quantum information processing systems are scaled to many qubits to reach their full potential, highly complex electronics are needed to control the complex circuitry. A team of researchers in the US (University of Rhode Island, University of Maryland, NIST, UCLA) considered a pair of quantum dot-based spin qubits that interact via microwave photons in a superconducting cavity and parametrically driven by separate external electric fields. For this system, they formulated a model for spin qubit entanglement in the presence of mutually off-resonant qubit and cavity frequencies. They showed that the sidebands generated via the driving fields enabled highly tunable qubit-qubit entanglement using only ac control and without requiring the qubit and cavity frequencies to be tuned into simultaneous resonance. They determined multiple common resonance conditions for the two driven qubits and the cavity and identified experimentally relevant parameter regimes that enabled the implementation of entangling gates with suppressed sensitivity to cavity photon occupation and decay. According to the researchers their approach provides a route toward scalability and modularity in spin-based quantum information processing through drive-enabled tunability that can also be implemented in micromagnet-free electron and hole systems for spin-photon coupling… read more. Open Access TECHNICAL ARTICLE
Schematic illustration of a system for cavity-mediated coupling of two parametrically driven quantum dot spin qubits via sidebands. Credit: PRX Quantum 5, 020339, 21 May 2024Â