Quantum Information Science news
Metrology papers published in Physical Review A
Two metrology papers from the group have recently been published in Physical Review A.
In "Quantum enhanced estimation of diffusion" [published as Phys. Rev. A 100 022129 (2019)] Dominic and Animesh, along with (now) former PDRA Christos Gagatsos and collaborators from the European Space Agency consider using a mechanical system to estimate diffusive processes. This work looks at methods to improve the precision of such experiments, with potential applications ranging from tracking in biological systems, to searching for dark matter, and tests of fundamental physics including collapse models. Using the phase space representation of continuous variable quantum states, they demonstrated how squeezing can be used to increase precision and that measurements such as measuring an arbitrary quadrature have substantial improvements over measuring position. These observations could improve the power of proposed experiments such as the space-based MAQRO to produce strong tests of proposed collapse models like continuous spontaneous localisation.
In "Fault-tolerant quantum metrology" [published as Phys. Rev. A 100 022335 (2019)] Theodoros and Animesh introduce an approach to integrate fault-tolerance into metrology schemes. They consider a bit-wise approach to phase estimation and present a fault-tolerant form of the phase estimation scheme. For estimating a given number of bits the fault-tolerant encoding then enables the estimate to converge at levels of noise beyond that which the non-fault tolerant approach converges for. This allows the fault-tolerant scheme to give a more precise estimate of the phase for the same levels of noise.