Quantum Feedback Control
Feedback control is the process
of monitoring a system and using the information, as it is being
obtained (that is, in real-time) to apply forces to the system to
control it's behavior. Generally the objective is to get the system to
maintain a desired evolution in the presence of noise or other
uncertainties. The subject of feedback control in classical systems is
well-developed, and feedback control is essential in many electrical
and mechanical devices. The application of feedback control to
quantum systems is the subject of quantum feedback control.
The key property that distinguishes quantum feedback control from its
classical counterpart is that, in general, measurements cause
disturbance in quantum systems. That is, the measurement that is part
of the feedback loop will introduce noise into the system.
Understanding feedback control in quantum systems therefore involves
understanding not only how best to use the information obtained by the
measurement, but how to optimize the measurement to minimize the
disturbance.
Another important application of feedback control in quantum systems is
adaptive measurement. In this case the measurement (or equivalently the
system) is altered in real time so as to achieve an effective
measurement process that may be difficult to obtain in any other way.
The group at UMass Boston is working on the theory of feedback for
stabilization and on adaptive measurements, as well as specific
applications in atom optics and QNEMS. |
Selected Publications
Feedback Control of Non-linear
Quantum Systems: a Rule of Thumb
K. Jacobs and A. P. Lund
Phys. Rev. Lett. 99,
020501 (2007)
Rapid
State-Reduction of Quantum Systems
Using Feedback Control
J. Combes and
K. Jacobs,
Phys. Rev.
Lett. 96 ,
010504 (2006)
Quantum Feedback Control of Atomic Motion in an Optical Cavity
D.A. Steck, K. Jacobs, H. Mabuchi, S. Habib and T.
Bhattacharya,
Phys. Rev. Lett. 92,
223004 (2004)
Feedback-Control of Quantum
Systems Using Continuous State-Estimation
A. Doherty and K. Jacobs,
Phys Rev. A 60,
2700 (1999)
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