Stabilization of Kerr-cat qubits with quantum circuit refrigerator

  1. Shumpei Masuda,
  2. Shunsuke Kamimura,
  3. Tsuyoshi Yamamoto,
  4. Takaaki Aoki,
  5. and Akiyoshi Tomonaga
A periodically-driven superconducting nonlinear resonator can implement a Kerr-cat qubit, which provides a promising route to a quantum computer with a long lifetime. However, the system

Flux-driven Josephson parametric amplifiers: Hysteretic flux response and nondegenerate gain measurements

  1. Stefan Pogorzalek,
  2. Kirill G. Fedorov,
  3. Ling Zhong,
  4. Jan Goetz,
  5. Friedrich Wulschner,
  6. Michael Fischer,
  7. Peter Eder,
  8. Edwar Xie,
  9. Kunihiro Inomata,
  10. Tsuyoshi Yamamoto,
  11. Yasunobu Nakamura,
  12. Achim Marx,
  13. Frank Deppe,
  14. and Rudolf Gross
Josephson parametric amplifiers (JPA) have become key devices in quantum science and technology with superconducting circuits. In particular, they can be utilized as quantum-limited

Single microwave-photon detector using an artificial Λ-type three-level system

  1. Kunihiro Inomata,
  2. Zhirong Lin,
  3. Kazuki Koshino,
  4. William D. Oliver,
  5. Jaw-Shen Tsai,
  6. Tsuyoshi Yamamoto,
  7. and Yasunobu Nakamura
Single photon detection is a requisite technique in quantum-optics experiments in both the optical and the microwave domains. However, the energy of microwave quanta are four to five

Dressed-state engineering for continuous detection of itinerant microwave photons

  1. Kazuki Koshino,
  2. Zhirong Lin,
  3. Kunihiro Inomata,
  4. Tsuyoshi Yamamoto,
  5. and Yasunobu Nakamura
We propose a scheme for continuous detection of itinerant microwave photons in circuit quantum electrodynamics. In the proposed device, a superconducting qubit is coupled dispersively

Theory of microwave single-photon detection using an impedance-matched Λ system

  1. Kazuki Koshino,
  2. Kunihiro Inomata,
  3. Zhirong Lin,
  4. Yasunobu Nakamura,
  5. and Tsuyoshi Yamamoto
By properly driving a qubit-resonator system in the strong dispersive regime, we implement an „impedance-matched“ Λ system in the dressed states, where a resonant single