Me: From: a Quantum Bang-Bang control to prevent information loss. “Dynamic Decoupling”. Thermostat. Fast reaction* Paper: Dynamical suppression of decoherence in two-state quantum systems Lorenza Viola, Seth Lloyd (Dept. of Mechanical Engineering, MIT) The dynamics of a decohering two-level system driven by a suitable control Hamiltonian is studied. The control procedure is implemented as a sequence of radiofrequency pulses that repetitively flip the state of the system, a technique that can be termed quantum “bang-bang” control after its classical analog. Decoherence introduced by the system’s interaction with a quantum environment is shown to be washed out completely in the limit of continuous flipping and greatly suppressed provided the interval between the pulses is made comparable to the correlation time of the environment. The model suggests a strategy to fight against decoherence that complements existing quantum error-correction techniques. https://arxiv.org/abs/quant-ph/9803057 ——————- Me: *”Bang–bang controls frequently arise in minimum-time problems. For example, if it is desired for a car starting at rest to arrive at a certain position ahead of the car in the shortest possible time, the solution is to apply maximum acceleration until the unique switching point, and then apply maximum braking to come to rest exactly at the desired position.” -Wikipedia on Bang Bang Controls.

Me: From: a Quantum Bang-Bang control to prevent information loss. “Dynamic Decoupling”. Thermostat. Fast reaction* Paper: Dynamical suppression of decoherence in two-state quantum systems Lorenza Viola, Seth Lloyd (Dept. of Mechanical Engineering, MIT) The dynamics of a decohering two-level system driven by a suitable control Hamiltonian is studied. The control procedure is implemented as a sequence of radiofrequency pulses that repetitively flip the state of the system, a technique that can be termed quantum “bang-bang” control after its classical analog. Decoherence introduced by the system’s interaction with a quantum environment is shown to be washed out completely in the limit of continuous flipping and greatly suppressed provided the interval between the pulses is made comparable to the correlation time of the environment. The model suggests a strategy to fight against decoherence that complements existing quantum error-correction techniques. https://arxiv.org/abs/quant-ph/9803057 ——————- Me: *”Bang–bang controls frequently arise in minimum-time problems. For example, if it is desired for a car starting at rest to arrive at a certain position ahead of the car in the shortest possible time, the solution is to apply maximum acceleration until the unique switching point, and then apply maximum braking to come to rest exactly at the desired position.” -Wikipedia on Bang Bang Controls.

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