Query: Ultrastrong coupling between light and matter

Candidate papers:

abstract: Light matter coupling with strength comparable to the bare transition frequencies of the system is called ultrastrong. This Review surveys how experiments have realized ultrastrong coupling in the past decade, the new phenomena predicted in this regime and the applications it enables.AbstractUltrastrong coupling between light and matter has, in the past decade, transitioned from a theoretical idea to an experimental reality. It is a new regime of quantum light matter interaction, which goes beyond weak and strong coupling to make the coupling strength comparable to the transition frequencies in the system. The achievement of weak and strong coupling has led to increased control of quantum systems and to applications such as lasers, quantum sensing, and quantum information processing. Here we review the theory of quantum systems with ultrastrong coupling, discussing entangled ground states with virtual excitations, new avenues for nonlinear optics, and connections to several important physical models. We also overview the multitude of experimental setups, including superconducting circuits, organic molecules, semiconductor polaritons, and optomechanical systems, that have now achieved ultrastrong coupling. We conclude by discussing the many potential applications that these achievements enable in physics and chemistry.Key pointsUltrastrong coupling (USC) can be achieved by coupling many dipoles to light, or by using degrees of freedom whose coupling is not bounded by the smallness of the fine structure constant.The highest light matter coupling strengths have been measured in experiments with Landau polaritons in semiconductor systems and in setups with superconducting quantum circuits.With USC, standard approximations break down, allowing processes that do not conserve the number of excitations in the system, leading to a ground state that contains virtual excitations.Potential applications of USC include fast and protected quantum information processing, nonlinear optics, modified chemical reactions and the enhancement of various quantum phenomena.Now that USC has been reached in several systems, it is time to experimentally explore the new phenomena predicted for this regime and to find their useful applications.
author_names: Anton Frisk Kockum

Adam Miranowicz

Simone De Liberato

Salvatore Savasta

Franco Nori
title: Ultrastrong coupling between light and matter
year: 2018

abstract: The following changes have been made to the original article: in the lower right panel of Fig. 1, opoelectrics has been corrected to optoelectronics; in the Box 1 footnote, rotating wave approximation has been corrected to rotating wave approximation; in equation B1.3, an operator symbol has been added to the last term; and in the third paragraph of Box 2, |j |n> was changed to |j> |n> This has been corrected in the HTML and PDF versions of the article.
author_names: Anton Frisk Kockum

Adam Miranowicz

Simone De Liberato

Salvatore Savasta

Franco Nori
title: Publisher Correction: Ultrastrong coupling between light and matter
venue: Nature Reviews Physics
year: 2019

abstract: The strength of the coupling between an atom and a single electromagnetic field mode is defined as the ratio of the vacuum Rabi frequency to the Larmor frequency, and is determined by a small dimensionless physical constant, the fine structure constant \alpha =Z_{vac} 2R_{K} a Z vac 2 R K On the other hand, the quantum circuit including Josephson junctions behaving as artificial atoms and it can be coupled to the electromagnetic field with arbitrary strength (Devoret et al. 2007) Therefore, the circuit quantum electrodynamics (circuit QED) is extremely suitable for studying much stronger light matter interaction.
author_names: Kouichi Semba
title: Emerging Ultrastrong Coupling Between Light and Matter Observed in Circuit Quantum Electrodynamics
year: 2020

abstract: Recent experiments have demonstrated that light and matter can mix together to an extreme degree, and previously uncharted regimes of light matter interactions are currently being explored in a variety of settings. The so called ultrastrong coupling (USC) regime is established when the light matter interaction energy is a comparable fraction of the bare frequencies of the uncoupled systems. Furthermore, when the interaction strengths become larger than the bare frequencies, the deep strong coupling (DSC) regime emerges. This article reviews advances in the field of the USC and DSC regimes, in particular, for light modes confined in cavities interacting with two level systems. An overview is first provided on the theoretical progress since the origins from the semiclassical Rabi model until recent developments of the quantum Rabi model. Next, several key experimental results from a variety of quantum platforms are described, including superconducting circuits, semiconductor quantum wells, and other hybrid quantum systems. Finally, anticipated applications are highlighted utilizing USC and DSC regimes, including novel quantum optical phenomena, quantum simulation, and quantum computation.
author_names: P Forn-D'iaz

Lucas Lamata

Enrique Rico

Junichiro Kono

Enrique Solano
title: Ultrastrong coupling regimes of light matter interaction
venue: Reviews of Modern Physics
year: 2019

author_names: R Sagastizabal

N K Langford

Marios Kounalakis

Christian Dickel

A Bruno

F Luthi

David J Thoen

Akira Endo

Leonardo DiCarlo
title: Experimentally simulating the dynamics of quantum light and matter at ultrastrong coupling using circuit QED (2) light dynamics and light matter entanglement
year: 2017

abstract: Vincenzo Macri, Fabrizio Minganti, 2, Anton Frisk Kockum, Alessandro Ridolfo, 5 Salvatore Savasta, 6 and Franco Nori 7, 8 Theoretical Quantum Physics Laboratory, RIKEN, Wako shi, Saitama 351 0198, Japan Institute of Physics, Ecole Polytechnique Federale de Lausanne (EPFL) CH 1015 Lausanne, Switzerland Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412 96 Gothenburg, Sweden Dipartimento di Fisica e Astronomia, Universita di Catania, 95123 Catania, Italy INFN Sezione Catania, Catania, Italy Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Universita di Messina, I 98166 Messina, Italy RIKEN Center for Quantum Computing (RQC) Wakoshi, Saitama 351 0198, Japan Physics Department, The University of Michigan, Ann Arbor, Michigan 48109 1040, USA (Dated: July 20, 2021)
author_names: Vincenzo Macri

Fabrizio Minganti

Anton Frisk Kockum

Alessandro Ridolfo

Salvatore Savasta

Franco Nori
title: Revealing higher order light and matter energy exchanges using quantum trajectories in ultrastrong coupling
year: 2021

abstract: In the ultrastrong light matter coupling regime, non perturbative effects are observed even for large detuning of the light and matter frequencies. In this regime, the rotating wave approximation breaks down and the contributions of counter rotating and diamagnetic terms lead to significant spectral modifications. Using split ring resonators coupled to the cyclotron transition in a two dimensional electron gas, we show that the diamagnetic terms lead to an asymmetry between the light and matter branches. Our system allows tuning both, the cavity and the matter frequency over more than two octaves. We find, that the assumption of constant coupling rate O as function of detuning is not generally valid for the large frequency range relevant to ultrastrong coupling phenomena.
author_names: Curdin Maissen

Giacomo Scalari

Mattias Beck

Jerome Faist
title: Asymmetry in polariton dispersion as function of light and matter frequencies in the ultrastrong coupling regime
year: 2017

author_names: Marios Kounalakis

N K Langford

R Sagastizabal

Christian Dickel

A Bruno

F Luthi

David J Thoen

Akira Endo

Leonardo DiCarlo
title: Experimentally simulating the dynamics of quantum light and matter at ultrastrong coupling using circuit QED (1) implementation and matter dynamics
year: 2017

abstract: In this paper we propose an efficient method for creating macroscopically distinct mechanical superposition states in an ultra strongly coupled light matter system. By modulating the opto mechanical coupling sinusoidally, the radiation pressure can be turned into a built in resonant driving force effectively. Thus the mechanical displacement can be significantly amplified.
author_names: Li Zheng

Dong-ni Chen

Zhenyun Peng

Ying Shi

Yujie Liu

Ying-Dan Wang
title: Macroscopic Quantum Superposition in Opto Mechanical System with Ultrastrong Coupling Light Matter Interaction
year: 2020

abstract: In a recent work of ours [Phys. Rev. Lett. 112, 073601 (2014) we generalized the Power Zineau Woolley gauge to describe the electrodynamics of atoms in an arbitrary confined geometry. Here we complement the theory by proposing a tractable form of the polarization field to represent atomic material with well defined intra atomic potential. The direct electrostatic dipole dipole interaction between the atoms is canceled. This theory yields a suitable framework to determine limitations on the light matter coupling in quantum optical models with discernible atoms. We find that the superradiant criticality is at the border of covalent molecule formation and crystallization.
author_names: Andras Vukics

Tobias Griesser

Peter Domokos
title: Fundamental limitation of ultrastrong coupling between light and atoms
year: 2015