A Nonlinear Charge and Flux Tunable Cavity Derived from an Embedded Cooper Pair Transistor

  1. B. L. Brock,
  2. Juliang Li,
  3. S. Kanhirathingal,
  4. B. Thyagarajan,
  5. William F. Braasch Jr.,
  6. M. P. Blencowe,
  7. and A. J. Rimberg
We introduce the cavity-embedded Cooper pair transistor (cCPT), a device which behaves as a highly nonlinear microwave cavity whose resonant frequency can be tuned both by charging

Frequency Fluctuations in Tunable Superconducting Microwave Cavities

  1. B. L. Brock,
  2. M. P. Blencowe,
  3. and A. J. Rimberg
We present a model for measurements of the scattering matrix elements of tunable microwave cavities in the presence of resonant frequency fluctuations induced by fluctuations in the

Mechanically Generating Entangled Photons from the Vacuum: A Microwave Circuit-Acoustic Resonator Analogue of the Unruh Effect

  1. Hui Wang,
  2. M. P. Blencowe,
  3. C. M. Wilson,
  4. and A. J. Rimberg
We consider a model for an oscillatory, relativistic accelerating photodetector inside a cavity and show that the entangled photon pair production from the vacuum (Unruh effect) can

Quantum Dynamics of a Josephson Junction-Driven Cavity Mode System in the Presence of Voltage Bias Noise

  1. Hui Wang,
  2. M. P. Blencowe,
  3. A. D. Armour,
  4. and A. J. Rimberg
We give a semiclassical analysis of the average photon number as well as photon number variance (Fano factor F) for a Josephson-junction (JJ) embedded microwave cavity system, wherethe JJ is subject to a fluctuating (i.e. noisy) bias voltage with finite dc average. Through the ac Josephson effect, the dc voltage bias drives the effectively nonlinear microwave cavity mode into an amplitude squeezed state (F<1), as has been established previously [A. D. Armour, et al., Phys. Rev. Lett. 111, 247001 (2013)], but bias noise acts to degrade this squeezing. We find that the sensitivity of the Fano factor to bias voltage noise depends qualitatively on which stable fixed point regime the system is in for the corresponding classical nonlinear steady state dynamics. Furthermore, we show that the impact of voltage bias noise is most significant when the cavity is excited to states with large average photon number.[/expand]