Dynamics of many-body photon bound states in chiral waveguide QED

authored by: Sahand Mahmoodian, Giuseppe Calajó, Darrick E. Chang, Klemens Hammerer, Anders S. Sørensen
Abstract: We theoretically study the few- and many-body dynamics of photons in chiral waveguides. In particular, we examine pulse propagation through an ensemble of N two-level systems chirally coupled to a waveguide. We show that the system supports correlated multiphoton bound states, which have a well-defined photon number n and propagate through the system with a group delay scaling as 1/n2. This has the interesting consequence that, during propagation, an incident coherent-state pulse breaks up into different bound-state components that can become spatially separated at the output in a sufficiently long system. For sufficiently many photons and sufficiently short systems, we show that linear combinations of n-body bound states recover the well-known phenomenon of mean-field solitons in self-induced transparency. Our work thus covers the entire spectrum from few-photon quantum propagation, to genuine quantum many-body (atom and photon) phenomena, and ultimately the quantum-to-classical transition. Finally, we demonstrate that the bound states can undergo elastic scattering with additional photons. Together, our results demonstrate that photon bound states are truly distinct physical objects emerging from the most elementary light-matter interaction between photons and two-level emitters. Our work opens the door to studying quantum many-body physics and soliton physics with photons in chiral waveguide QED.
Organisation(s): Institute of Theoretical Physics
Institute of Gravitation Physics
CRC 1227 Designed Quantum States of Matter (DQ-mat)
External Organisation(s): Barcelona Institute of Science and Technology (BIST)
Catalan Institution for Research and Advanced Studies (ICREA)
University of Copenhagen
Type: Article
Journal: Physical Review X
Volume: 10
ISSN: 2160-3308
Publication date: 14.07.2020
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physics and Astronomy(all)
Electronic version(s): https://doi.org/10.1103/PhysRevX.10.031011 (Access: Open)

BibTeX

@article{163d2dbae85744158e358756cae1bb60,
title = "Dynamics of many-body photon bound states in chiral waveguide QED",
abstract = "We theoretically study the few- and many-body dynamics of photons in chiral waveguides. In particular, we examine pulse propagation through an ensemble of N two-level systems chirally coupled to a waveguide. We show that the system supports correlated multiphoton bound states, which have a well-defined photon number n and propagate through the system with a group delay scaling as 1/n2. This has the interesting consequence that, during propagation, an incident coherent-state pulse breaks up into different bound-state components that can become spatially separated at the output in a sufficiently long system. For sufficiently many photons and sufficiently short systems, we show that linear combinations of n-body bound states recover the well-known phenomenon of mean-field solitons in self-induced transparency. Our work thus covers the entire spectrum from few-photon quantum propagation, to genuine quantum many-body (atom and photon) phenomena, and ultimately the quantum-to-classical transition. Finally, we demonstrate that the bound states can undergo elastic scattering with additional photons. Together, our results demonstrate that photon bound states are truly distinct physical objects emerging from the most elementary light-matter interaction between photons and two-level emitters. Our work opens the door to studying quantum many-body physics and soliton physics with photons in chiral waveguide QED.",
author = "Sahand Mahmoodian and Giuseppe Calaj{\'o} and Chang, {Darrick E.} and Klemens Hammerer and S{\o}rensen, {Anders S.}",
note = "Funding information: The authors thank Mantas ?epulkovskis, Peter Lodahl, Sebastian Hofferberth, Hanna le Jeannic, Johannes Bjerlin, L. Henriet, and J. Douglas for fruitful discussions. S. M. and K. H. acknowledge funding from DFG through Grant No. CRC 1227 DQ-mat, Projects No. A05 and A06, and “Nieders{\"a}chsisches Vorab” through the “Quantum-and Nano-Metrology.” G. C. and D. E. C. acknowledge support from ERC Starting Grant FOQAL, MINECO Severo Ochoa Grant No. SEV-2015-0522, CERCA Programme/Generalitat de Catalunya, Fundaci{\'o} Privada Cellex, Fundaci{\'o} Mir-Puig, Fundaci{\'o}n Ram{\'o}n Areces Project CODEC, European Quantum Flagship Project QIA, QuantumCAT (funded within the framework of the ERDF Operational Program of Catalonia), and Plan Nacional Grant ALIQS, funded by Ministerio de Ciencia, Innovaci{\'o}n, y Universidades (MCIU), Agencia Estatal de Investigaci{\'o}n (AEI), and Fondo Europeo de Desarrollo Regional (FEDER). A. S. S. acknowledges support from the Danish National Research Foundation (Center of Excellence Hy-Q).",
year = "2020",
month = jul,
day = "14",
doi = "10.1103/PhysRevX.10.031011",
language = "English",
volume = "10",
journal = "Physical Review X",
issn = "2160-3308",
publisher = "American Physical Society",
number = "3",
}