Telling different unravelings apart via nonlinear quantum-trajectory averages
The Gorini-Kossakowski-Sudarshan-Lindblad master equation (ME) governs the density matrix of open quantum systems (OQSs). When an OQS is subjected to weak continuous measurement, its state evolves as a stochastic quantum trajectory, whose statistical average solves the ME. The ensemble of such trajectories is termed an unraveling of the ME. We propose a method to operationally distinguish unravelings produced by the same ME in different measurement scenarios, using nonlinear averages of observables over trajectories. We apply the method to the paradigmatic quantum nonlinear system of resonance fluorescence in a two-level atom. We compare the Poisson-type unraveling, induced by direct detection of photons scattered from the two-level emitter, and the Wiener-type unraveling, induced by phase-sensitive detection of the emitted field. We show that a quantum-trajectory-averaged variance is able to distinguish these measurement scenarios. We evaluate the performance of the method, which can be readily extended to more complex OQSs, under a range of realistic experimental conditions. Published by the American Physical Society 2024
Authors
- Samuele Grandi (ORCID: https://orcid.org/0000-0002-6986-8292)
- Th. K. Mavrogordatos (ORCID: https://orcid.org/0000-0003-1739-7430)
- Miguel Ángel García-March (ORCID: https://orcid.org/0000-0001-7092-838X)
- Piotr Sierant (ORCID: https://orcid.org/0000-0001-9219-7274)
- Maciej Lewenstein (ORCID: https://orcid.org/0000-0002-0210-7800)
- Morgan W. Mitchell (ORCID: https://orcid.org/0000-0001-8949-9407)
- Dustin Keys (ORCID: https://orcid.org/0000-0002-5265-2719)
- Eloy Piñol (ORCID: https://orcid.org/0000-0002-3763-175X)
- Jan Wehr (ORCID: https://orcid.org/0000-0003-1375-9676)
- Romain Veyron (ORCID: https://orcid.org/0000-0002-8086-9691)
Institutions
- Institució Catalana de Recerca i Estudis Avançats (ES)
- University of Arizona (US)
- Institute of Photonic Sciences (ES)
- AlbaNova (SE)
- Universitat Politècnica de València (ES)
Publication Details
- Journal
- Physical Review Research
- Published
- 2024-09-06
- DOI
- https://doi.org/10.1103/physrevresearch.6.l032057
- Citations
- 2
- Primary Topic
- Quantum Information and Cryptography
- Type
- article
- Field-Weighted Citation Impact
- 0.69
Funders
- National Science Foundation
- “la Caixa” Foundation
- Centres de Recerca de Catalunya
- Institut de Ciències Fotòniques
- European Commission
- The Ministry of Economic Affairs and Employment
- Generalitat de Catalunya
- Federación Española de Enfermedades Raras
- Generalitat Valenciana
- Ministerio de Ciencia e Innovación
- Barcelona Supercomputing Center
- QuantERA
- European Climate, Infrastructure and Environment Executive Agency
- Horizon 2020 Framework Programme
- HORIZON EUROPE Framework Programme
- Agència de Gestió d'Ajuts Universitaris i de Recerca
- European Regional Development Fund
- Agencia Estatal de Investigación