Non-Markovian dynamics of a qubit due to accelerated light in a lattice

Year: 2025

Authors: Pinto M.A., Sferrazza G.L., De Bernardis D., Ciccarello F.

Autors Affiliation: Univ Palermo, Dipartimento Fis & Chim Emilio Segre, Via Archirafi 36, I-90123 Palermo, Italy; Natl Inst Opt CNR INO, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; European Lab Nonlinear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Ist Nanosci CNR, NEST, Piazza S Silvestro 12, I-56127 Pisa, Italy.

Abstract: We investigate the emission of a qubit weakly coupled to a one-band coupled-cavity array where, due to an engineered gradient in the cavity frequencies, photons are effectively accelerated by a synthetic force F. For strong F, a reversible emission described by an effective Jaynes-Cummings model occurs, causing a chiral time-periodic excitation of an extensive region of the array, either to the right or to left of the qubit depending on its frequency. For weak values of F instead, a complex non-Markovian decay with revivals shows up. This is reminiscent of dynamics induced by mirrors in standard waveguides, despite the absence of actual mirrors, and can be attributed to the finite width of the energy band which confine the motion of the emitted photon. In a suitable regime, the decay is well described by a delay differential equation formally analogous to the one governing the decay of an atom in a multi-mode cavity where the cavity length and time taken by a photon to travel between the two mirrors are now embodied by the amplitude and period of Bloch oscillations, respectively.

Journal/Review: PHYSICA SCRIPTA

Volume: 100 (10)      Pages from: 105304-1  to: 105304-16

More Information: MP, GLS and FC acknowledge financial support from European Union-Next Generation EU through projects: Eurostart 2022 ’Topological qubit-photon interactions for quantum technologies’; PRIN 2022-PNRR No. P202253RLY ’Harnessing topological phases for quantum technologies’; THENCE-Partenariato Esteso NQSTI-PE00000023-Spoke 2 ’Taming and harnessing decoherence in complex networks’. DDB acknowledges funding from the European Union – NextGeneration EU, Integrated infrastructure initiative in Photonic and Quantum Sciences – I-PHOQS [IR0000016, ID D2B8D520, CUP B53C22001750006].
KeyWords: non-markovian; quantum optics; waveguide qed; open quantum systems
DOI: 10.1088/1402-4896/ae0d12