Journal
PHYSICAL REVIEW A
Volume 92, Issue 6, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevA.92.063801
Keywords
-
Categories
Funding
- Joint Quantum Institute
- State of Maryland through the Center for Nanophysics and Advanced Materials
Ask authors/readers for more resources
We measure photon occupancy in a thin-film superconducting lumped element resonator coupled to a transmon qubit at 20mK and find a nonlinear dependence on the applied microwave power. The transmon-resonator system was operated in the strong dispersive regime, where the ac Stark shift (2 chi) due to a single microwave photon present in the resonator was larger than the linewidth (Gamma) of the qubit transition. When the resonator was coherently driven at 5.474 325 GHz, the transition spectrum of the transmon at 4.982 GHz revealed well-resolved peaks, each corresponding to an individual photon number-state of the resonator. From the relative peak heights we obtain the occupancy of the photon states and the average photon occupancy (n) over bar of the resonator. We observe a nonlinear variation of (n) over bar with the applied drive power P-rf for (n) over bar < 5 and compare our results to numerical simulations of the system-bath master equation in the steady state, as well as to a semiclassical model for the resonator that includes the Jaynes-Cummings interaction between the transmon and the resonator. We find good quantitative agreement using both models and analysis reveals that the nonlinear behavior is principally due to shifts in the resonant frequency caused by a qubit-induced Jaynes-Cummings nonlinearity.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available