Photonic and Phononic Technologies for Superconducting Quantum Information Systems
Abstract
The two most important technical goals in the field of quantum information science today are the creation of a quantum communication network and the construction of a general purpose quantum computer. How can cross-technology or hybrid systems enable these goals? First, a quantum network consisting of superconducting nodes joined by optical links requires a device capable of simultaneously operating in the quantum electrical and quantum optical domains. Second, a quantum computer based on superconducting circuits must realize complex connectivity graphs between a specified set of circuit elements while simultaneously providing a high degree of isolation from other parts of the circuit. One strategy to achieve more flexibility in connecting qubits and better qubit isolation is to convert quantum signals from the electrical domain into the acoustical domain. We propose an experimental and theoretical program to realize a hybrid superconducting quantum circuit technology with a quantum optical interface, enhanced quantum state storage, reduced device footprint, and improved qubit connectivity and isolation. Our approach integrates optomechanical, electro-optic, and acoustic devices with superconducting quantum circuits. Our effort consists of 5 Thrusts, two focused on quantum microwave-to-optical conversion (topic II.A.2.a), two involving the development of a hybrid qubit technology (topic II.A.2.C), and a fifth theory thrust that spans both II.A,2.a and U.A.2.C topical areas. In Thrusts 1 and 2 we seek to develop high-performance electrical-to-optical converters for quantum state transfer between the microwave signals of superconducting quantum circuits and flying qubits represented by telecom optical photons in fibers. Our efforts will focus both on modular mechanical-based converters (Thrust 1) as well as chip-based electro-optic converters (Thrust 2), and will involve a full-link strategy which includes the efficient coupling to and from transmon qubits and the converter. In addition, and intimately connected with our converter work, we propose in Thrusts 3 and 4 to develop a hybrid platform connecting transmon qubits to microwave acoustic elements such as surface-confined acoustic waveguides (Thrust 3) and ultra-coherent phononic bandgap cavities (Thrust 4). This circuit quantum acoustodynamics (CQAD) architecture has the potential to provide significant enhancements in footprint, coherence time, and cascadability over counterpart electrical devices. The experimental efforts in both the quantum converter and hybrid qubit platform will be complemented by a theoretical effort in Thrust 5. Theory will help develop optimized protocols and verification tests for the quantum electrical-to-optical converters, and will seek to develop new strategies for practical utilization of such devices in quantum networks. The primary, end-of-program goals for each experimental thrust are: (Tl) heralded creation of a single optical photon from a superconducting qubit utilizing a modular electro-optomechanical converter in combination with entanglement purification techniques, (T2) realization of a chipscale Si-on-LN electro-optic quantum converter with footprint less than 100(mu)m x100(mu)m and conversion efficiency better than 50%, (T3) demonstration of dispersive read-out and coherent qubitto-qubit coupling via surface-confined acoustic waves, (T4) demonstration of an integrated phonon memory for transmon qubits with qubit state storage and retrieval fidelity greater than 50% at storage times longer than 1 millisecond.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2018
- Source ID
- W911NF1810103
Entities
People
- Oskar Painter
Organizations
- Army Contracting Command
- California Institute of Technology
- National Security Agency