Taking Control of Superconducting Qubits

Event Date: 

Tuesday, June 4, 2013 - 4:00pm

Event Location: 

  • Broida 1640

Event Contact: 

Refreshments served at 3:40


Irfan Siddiqi - Quantum Nanoelectronics Laboratory, UC Berkeley

One of the fundamental challenges of quantum information processing is to sustain quantum coherence over a time interval practical for performing a computation or simulation.  Until now, this task has involved hardware development to minimize coupling to a dissipative environment which usually transforms a quantum superposition into a classical state. Recent advances in the development of robust quantum-noise-limited microwave amplifiers and quantum bits with lifetimes in excess of 100 microseconds have enabled the use of feedback to actively suppress decoherence. In particular, we have been able to tailor the dissipative environment, either via measurement or control pulses, to stabilize quantum superposition states and coherent oscillations indefinitely. Moreover, we have also reduced radiative decay by the squeezing the vacuum fluctuations incident on a quantum bit. These initial experiments suggest the plausibility of high fidelity feedback as a means to generate entanglement and to ultimately implement practical error correction.