Manipulating Fock states of a harmonic oscillator while preserving its linearity

作者：Juliusson K; Bernon S; Zhou X; Schmitt V; le Sueur H; Bertet P; Vion D^*; Mirrahimi M; Rouchon P; Esteve D

来源：Physical Review A, 2016, 94(6): 063861.

DOI：10.1103/PhysRevA.94.063861

We present a scheme for controlling the quantum state of a harmonic oscillator by coupling it to an anharmonic multilevel system (MLS) with first-to second-excited-state transition on resonance with the oscillator. In this scheme, which we call ef-resonant, the spurious oscillator Kerr nonlinearity inherited from the MLS is very small, while its Fock states can still be selectively addressed via an MLS transition at a frequency that depends on the number of photons. We implement this concept in a circuit-QED setup with a microwave three-dimensional cavity (the oscillator, with frequency 6.4 GHz and quality factor Q(O) = 2 x 10(6)) embedding a frequency tunable transmon qubit (the MLS). We characterize the system spectroscopically and demonstrate selective addressing of Fock states and a Kerr nonlinearity below 350 Hz. At times much longer than the transmon coherence times, a nonlinear cavity response with driving power is also observed and explained.

• 出版日期2016-12-29
• 单位中国地震局; INRIA; Mines Paristech