We solve two long-standing problems for stochastic descriptions of open quantum system dynamics. First, we find the classical stochastic processes corresponding to non-Markovian quantum state diffusion and non-Markovian quantum jumps in projective Hilbert space. Second, we show that the diffusive limit of non-Markovian quantum jumps can be taken on the projective Hilbert space in such a way that it coincides with non-Markovian quantum state diffusion. However, the very same limit taken on the Hilbert space leads to a completely new diffusive unraveling, which we call non-Markovian quantum diffusion. Further, we expand the applicability of non-Markovian quantum jumps and non-Markovian quantum diffusion by using a kernel smoothing technique allowing a significant simplification in their use. Lastly, we demonstrate the applicability of our results by studying a driven dissipative two level atom in a non-Markovian regime using all of the three methods.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.125.150403 | DOI Listing |
Nat Commun
January 2025
Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul, Korea.
Addressing and mitigating decoherence sources plays an essential role in the development of a scalable quantum computing system, which requires low gate errors to be consistently maintained throughout the circuit execution. While nuclear spin-free materials, such as isotopically purified silicon, exhibit intrinsically promising coherence properties for electron spin qubits, the omnipresent charge noise, when converted to magnetic noise under a strong magnetic field gradient, often hinders stable qubit operation within a time frame comparable to the data acquisition time. Here, we demonstrate both open- and closed-loop suppression techniques for the transduced noise in silicon spin qubits, resulting in a more than two-fold (ten-fold) improvement of the inhomogeneous coherence time (Rabi oscillation quality) that leads to a single-qubit gate fidelity of over 99.
View Article and Find Full Text PDFNanophotonics
June 2024
Department of Physics and Astronomy, University of Turku, Turku, Finland.
Hybridisation of the cavity modes and the excitons to polariton states together with the coupling to the vibrational modes determine the linear optical properties of organic semiconductors in microcavities. In this article we compute the refractive index for such system using the Holstein-Tavis-Cummings model and determine then the linear optical properties using the transfer matrix method. We first extract the parameters for the exciton in our model from fitting to experimentally measured absorption of a 2,7-bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl) fluorene (TDAF) molecular thin film.
View Article and Find Full Text PDFNanophotonics
June 2024
Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
The full information about the interaction between a quantum emitter and an arbitrary electromagnetic environment is encoded in the so-called spectral density. We present an approach for describing such interaction in any coupling regime, providing a Lindblad-like master equation for the emitter dynamics when coupled to a general nanophotonic structure. Our framework is based on the splitting of the spectral density into two terms.
View Article and Find Full Text PDFHeliyon
November 2024
Fundación Universitaria Los Libertadores, Facultad de Ingeniería y Ciencias Básicas, NanoTech Group, Cra.16 No. 63a-68, Bogotá, 111221, Cundinamarca, Colombia.
We incorporate non-Markovian profiles and Linear Response Theory to analyze memory effects in two-band topological quantum systems. Furthermore, we have applied a measure of non-Markovianity in terms of nonlinear optical spectroscopy. On the other hand, we resort to memory kernel, solve the integro-differential equation of the open two-band topological quantum system to describe the degrees of non-Markovianity, calculate response factors based on Linear Response Theory, and analyze non-Markovian dynamics by varying the parameters of the nonlinear spectroscopy environment of the respective open quantum system.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Zhejiang Laboratory, Hangzhou 311100, China.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!