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Piotr Olczykowski

Publications and source records attributed to Piotr Olczykowski.

4 recordsLinked to original sources
arXiv2020

Spin State Dynamics in a Bichromatic Microwave Field: Role of Bright and Dark States in coupling with Reservoir

Driving an open spin system by two strong, nearly degenerate fields enables addressing populations of individual spin states, characterisation of their interaction with thermal bath, and measurements of their relaxation/decoherence rates. With such addressing we observe nested magnetic resonances having nontrivial dependence on microwave field intensity: while the width of one of the resonances undergoes a strong power broadening, the other one exhibits a peculiar field-induced stabilization. We also observe light-induced narrowing of such composite resonances. The observations are explained by the dynamics of bright and dark superposition states and their interaction with reservoir.

quant-ph↗
arXiv2013

Real Spectral Triples over Noncommutative Bieberbach Manifolds

We classify and construct all real spectral triples over noncommutative Bieberbach manifolds, which are restrictions of irreducible real equivariant spectral triple over the noncommutative three-torus. We show that in the classical case the constructed geometries correspond exactly to spin structures over Bieberbach manifolds and the Dirac operators constructed for a flat metric.

math.QA↗
arXiv2010

On spectral action over Bieberbach manifolds

We compute the leading terms of the spectral action for orientable three dimensional Bieberbach manifolds first, using two different methods: the Poisson summation formula and the perturbative expansion. Assuming that the cut-off function is not necessarily symmetric we find that that the scale invariant part of the perturbative expansion might differ from the spectral action of the flat three-torus by the eta invariant.

math-ph↗