Quantum measurement and control
The state of the art in micro-opto-electro-mechanical systems allows for both actuation and measurement at the quantum regime. My PhD work was at this intersection, applying control theory within a quantum framework.
I investigated the theory of parametric amplification in such a system, and identified a regime in which noise in one phase of motion could be reduced arbitrarily below the standard quantum limit, by reading out its motion in the amplified phase (Szorkovszky et al., 2013). This can then be applied to entangled states (Szorkovszky et al., 2014), and quantum non-demolition measurement (Szorkovszky et al., 2014).
Subsequent work used a stochastic Schrödinger equation approach to derive optimal filters for tomographic reconstruction of nonclassical states (Warszawski et al., 2019).
References
2019
- Tomography of an optomechanical oscillator via parametrically amplified position measurementNew Journal of Physics, 2019
2014
- Mechanical entanglement via detuned parametric amplificationNew Journal of Physics, 2014
- Detuned mechanical parametric amplification as a quantum non-demolition measurementNew Journal of Physics, 2014
2013
- Strong thermomechanical squeezing via weak measurementPhysical review letters, 2013