Enhancing the cat's lifetime by squeezing

Cat states, which span high-dimensional Hilbert space, have been proven to be an attractive candidate for redundantly encoding in superconducting circuit quantum electrodynamics [1]. Usually, such cat states are easily affected by photon loss, which inevitably leads to the degradation of the encoded quantum information [2]. One promising technique to protect the quantum coherence of cat states is quadrature squeezing [3]. Here, we generate a squeezed cat state in a three-dimensional microwave cavity via a deterministic protocol, which consist of conditional displacements and qubit rotations. We show that squeezing enhances the coherence of cat states against photon loss [4]. This demonstration provides a useful technique to create more robust code words for quantum error correction and paves the way for robust information processing using bosonic states in superconducting cavities.