LMI Seminar: Composite pulses in quantum physics and classical optics

Abstract:

The technique of composite pulses replaces the single pulse used traditionally for driving a two-state quantum transition by a sequence of pulses with suitably chosen phases, which are used as control parameters for shaping the excitation profile in a desired manner.

Composite pulses produce unitary operations, which combine very high fidelity with robustness to parameter variations. We have developed a pool of composite pulses by using a novel SU(2) approach to design recipes for construction of single-qubit operations, including broadband, narrowband and passband pulses, universal composite pulses, composite adiabatic passage and composite STIRAP, some of which have already been demonstrated in experiments with doped solids. We have also designed efficient and robust composite techniques for construction of highly entangled states, e.g. Dicke and NOON states, and multi-qubit gates, e.g. C-phase, Toffoli, and generally C$^N$-phase gates. In this talk I will also describe applications of the idea of composite sequences beyond quantum physics. These include composite techniques for control of light propagation in waveguides, polarization optics and nonlinear frequency conversion, including recent experimental demonstrations.