Radiative decay of a superconducting qubit in squeezed vacuum

When the conventional vacuum fluctuations of the electromagnetic environment are replaced by the asymmetric, reduced fluctuations associated with squeezed vacuum, the radiative properties of an atom are predicted to be dramatically altered. We present measurements of the transverse and longitudinal decay rates of a superconducting qubit that couples predominantly to a continuum of squeezed electromagnetic vacuum. We use a lumped element Josephson parametric amplifier to squeeze vacuum fluctuations by up to 10dB with a bandwidth of 20 MHz. The amplifier output is directly coupled to a transmon qubit in a microwave cavity. We observe a dependence of the transverse decay rate on the relative angle between the squeezed axis and the qubit. In particular, at certain angles, we observe an improvement in the qubit T2 time above its nominal value.