238 research outputs found
Coherent interaction-free detection of microwave pulses with a superconducting circuit
We show that it is possible to ascertain the presence of a microwave pulse
resonant with the second transition of a superconducting transmon circuit,
while at the same time avoiding to excite the device onto the third level. In
contrast to standard interaction-free measurement setups, where the dynamics
involves a series of projection operations, our protocol employs a fully
coherent evolution, which results, surprisingly, in a higher efficiency.
Experimentally, this is done by using a series of Ramsey microwave pulses
coupled into the first transition and monitoring the ground-state population.Comment: 19 pages, 17 figures. Comments are welcome
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