Journal Article

Fast generation of Schrödinger cat states using a Kerr-tunable superconducting resonator

Xue, Hang, Roudsari, A. F., Delsing, Per, Lin, Z. R., Lu, Yong, He, X. L., Tsai, J. S., Wang, Z., Jiang, W. B., Bao, D. Q.

2023

Overview

Schrödinger cat states, quantum superpositions of macroscopically distinct classical states, are an important resource for quantum communication, quantum metrology and quantum computation. Especially, cat states in a phase space protected against phase-flip errors can be used as a logical qubit. However, cat states, normally generated in three-dimensional cavities and/or strong multi-photon drives, are facing the challenges of scalability and controllability. Here, we present a strategy to generate and preserve cat states in a coplanar superconducting circuit by the fast modulation of Kerr nonlinearity. At the Kerr-free work point, our cat states are passively preserved due to the vanishing Kerr effect. We are able to prepare a 2-component cat state in our chip-based device with a fidelity reaching 89.1% under a 96 ns gate time. Our scheme shows an excellent route to constructing a chip-based bosonic quantum processor. Schrodinger’s cat states constitute an important resource for quantum information processing, but present challenges in terms of scalabilty and controllability. Here, the authors exploit fast Kerr nonlinearity modulation to generate and store cat states in superconducting circuits in a more scalable way.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/766/483/2802 / 639/766/483/3925 / 639/766/483/481 / 639/925/927/1064 / Circuits / Controllability / Data processing / Evolution / Humanities and Social Sciences / Information processing / Kerr effects / Microprocessors / Modulation / multidisciplinary / Nonlinear systems / Nonlinearity / Quantum computing / Quantum phenomena / Qubits (quantum computing) / Schroedinger cat state / Science / Science (multidisciplinary) / Superconductivity