Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Cavity-modified oscillating bound states with a Λ -type giant emitter in a linear waveguide

Ge Sun, Ya Yang, Jing Li, Jing Lu, Lan Zhou

Published Mar 4, 2025• 14 citations
Publisher

Abstract

We study a system composed of a three-level giant atom (3GA), a waveguide initially in the vacuum state, and a single-mode cavity. The 3GA-cavity system is in a strong-coupling regime, and the distance between the coupling points is comparable to the coherent length of a spontaneously emitted photon. The dynamics of the 3GA and its radiative field in the waveguide for long times are analyzed in each subspace with only one excitation exchanged between the waveguide and the 3GA cavity. Besides the steady value, we also found an oscillatory character of the excited-state population, a signature of oscillating bound states which is generated by the superposition of two bound states in the continuum. The radiative field propagates in the cavitylike geometry formed by the coupling points. When one bound state is emergent, a sinelike interference pattern is visible for the emitted photon distribution in spacetime. An oscillatory character in time and a beat in space for the emitted photon distribution are observed when two bound states are emergent in a subspace. The wavelengths and the periods are controlled by the number of photons in the cavity.

DOI
10.1103/physreva.111.033701

Related papers

Cavity Modified Oscillating Bound States with a $Λ$-type giant emitter in a linear waveguide

Sun, Ge, Ya Jun Yang, Li, Jing +2 more

We study a system composed by a three-level giant atom (3GA), a waveguide initially in the vacuum state, and a single-mode cavity. The 3GA-cavity system is in a strong-coupling regime, and the distance between the coupling points is comparable to the coherent length of a spontaneously emitted photon. The dynamics of the 3GA and its radiative field in the waveguide for long time are analyzed. Besides the steady value, we also found an oscillatory character of the excited state population, a signature of oscillating bound states which is generated by the superposition of two bound states in the continuum. The radiative field propagates in the cavity-like geometry formed by the coupling points. When one bound state is emergent, a sine-like interference pattern is visible for the emitted field intensity in spacetime. An oscillatory character in time and a beat in space for the emitted field intensity are observed when two bound states are emergent in a subspace. The wavelengths and the periods are controlled by the number of the photons in the cavity.

arXiv:2406.17351•Jun 25, 2024•0 citations

Controlling radiative dynamics of a giant $Λ$-type atom via interference induced by the vacuum of a waveguide

Ci-Ming Deng, Ge Sun, Jing Lu +1 more

We investigate the dynamics of a $Λ$-type giant atom (GA) whose both transition coupled to the guided modes of a one-dimensional (1D) waveguide at two spatially separated points with the GA initially excited and the electromagnetic (EM) modes of waveguide in vacuum. The spontaneous emission properties of this GA is investigated by solving the delay-differential equation for the amplitude of the 3GA in its excited state. Signatures of non-Markovian behavior is manifested in a population trapping in the excited state of the GA in the regime where the distance $d$ of the coupling points is smaller or comparable to the coherent length $L$ characterizing the width of the emitted wave packet. And an exact Markovian dynamics is also found when $d\geq L$ via the inference by adjusting the energy spacing and the inherent time delay besides the complex phases in the atom-light coupling, matching the behavior of a small atom coupled to a waveguide.

quant-pharXiv:2606.25587•Jun 25, 2026•0 citations

Emergent Oscillating bound states in a semi-infinite linear waveguide with a point-like $Λ$-type quantum emitter driven by a classical field

Yuping He, Sun, Ge, Li, Jing +3 more

An oscillating bound state is a phenomenon where excitations mediated by the continuum modes oscillate persistently. Although it is generated by the superposition of two bound states in the continuum (BICs), such phenomenon is said to be unique to giant atoms. We present the phenomenon of an oscillating bound state with an alternative waveguide QED system, which is a one-dimensional semi-infinite waveguide coupled to a \textit{point-like} quantum emitter. This \textit{point-like} quantum emitter is $Λ$-type quantum system with one transition driven by a classical field.

arXiv:2405.17994•May 28, 2024•0 citations

Oscillating bound states in waveguide QED systems with two giant atoms

Liangbin He, T J Li, Zhen Yi +2 more

Abstract We investigate the dynamics of two two-level giant atoms coupled to a one-dimensional waveguide in separate and braided configurations. Using the resolvent method, the quantum dynamics are determined by the poles of the Green’s function. We identify conditions under which three real poles with distinct eigenfrequencies emerge, corresponding to three bound states in the continuum (BICs). Their superposition gives rise to oscillating BICs. In this regime, the atomic excitation oscillates between the two atoms, while the photon field remains confined between the coupling points and exhibits persistent oscillations. The maxima of the photon field distribution coincide with those of the atomic excitations, reflecting the atom-photon bound-state nature. The revival of the photon distribution reveals the coherent interaction between the two giant atoms mediated by the BICs. This work broadens the fields of quantum information storage and manipulation by leveraging larger Hilbert spaces enabled by multiple nonradiative BICs.

Chinese Physics B•Jun 22, 2026•0 citations

Emergent Oscillating Bound States in a Semi‐Infinite Linear Waveguide with a Point‐Like Λ$\Lambda$‐Type Quantum Emitter Driven by a Classical Field

Yuping He, Ge Sun, Jing Li +3 more

Abstract An oscillating bound state is a phenomenon where excitations mediated by the continuum modes oscillate persistently. Although it is generated by the superposition of two bound states in the continuum (BICs), such phenomenon is said to be unique to giant atoms. The phenomenon of an oscillating bound state with an alternative waveguide QED system is presented, which is a one dimensional (1D) semi‐infinite waveguide coupled to a point‐like quantum emitter. This point‐like quantum emitter is ‐type quantum system with one transition driven by a classical field.

Advanced Quantum Technologies•Feb 6, 2025•8 citations

Multi-emitter oscillating bound states in Waveguide QED

Sergi Terradas-Briansó, Carlos A. González-Gutiérrez, Iván Huarte +2 more

Waveguide quantum electrodynamics platforms have emerged as promising candidates for exploring and implementing non-Markovian quantum phenomena. In this work, we investigate the formation and dynamics of superpositions of bound states in a cavity array waveguide coupled to two spatially separated quantum emitters. By tuning the system parameters, we show that spontaneous emission can drive the system into non-local equilibrium states in which both photonic and emitter populations exhibit persistent oscillations. These states arise from the coexistence of bound states embedded in the energy continuum and bound states outside it, leading to hybrid oscillatory modes. We analytically derive the conditions required for the emergence of these states, numerically simulate their formation through spontaneous emission, and predict their long-time behaviour. Our results demonstrate that such bound-state superpositions enable the generation of emitter-emitter interaction through free evolution, while supporting oscillatory breathing modes of the photon density between the emitters.

quant-pharXiv:2602.16032•Feb 19, 2026•0 citations
We study a system composed of a three-level giant atom (3GA), a waveguide initially in the vacuum state, and a single-mode cavity. The 3GA-cavity system is in a strong-coupling regime, and the distance between the coupling points is comparable to the coherent length of a spontaneously emitted photon. The dynamics of the 3GA and its radiative field in the waveguide for long times are analyzed in each subspace with only one excitation exchanged between the waveguide and the 3GA cavity. Besides the steady value, we also found an oscillatory character of the excited-state population, a signature of oscillating bound states which is generated by the superposition of two bound states in the continuum. The radiative field propagates in the cavitylike geometry formed by the coupling points. When one bound state is emergent, a sinelike interference pattern is visible for the emitted photon distribution in spacetime. An oscillatory character in time and a beat in space for the emitted photon distribution are observed when two bound states are emergent in a subspace. The wavelengths and the periods are controlled by the number of photons in the cavity.
Cavity Modified Oscillating Bound States with a ΛΛΛ-type giant emitter in a linear waveguide
We study a system composed by a three-level giant atom (3GA), a waveguide initially in the vacuum state, and a single-mode cavity. The 3GA-cavity system is in a strong-coupling regime, and the distance between the coupling points is comparable to the coherent length of a spontaneously emitted photon. The dynamics of the 3GA and its radiative field in the waveguide for long time are analyzed. Besides the steady value, we also found an oscillatory character of the excited state population, a signature of oscillating bound states which is generated by the superposition of two bound states in the continuum. The radiative field propagates in the cavity-like geometry formed by the coupling points. When one bound state is emergent, a sine-like interference pattern is visible for the emitted field intensity in spacetime. An oscillatory character in time and a beat in space for the emitted field intensity are observed when two bound states are emergent in a subspace. The wavelengths and the periods are controlled by the number of the photons in the cavity.
Controlling radiative dynamics of a giant ΛΛΛ-type atom via interference induced by the vacuum of a waveguide
We investigate the dynamics of a ΛΛΛ-type giant atom (GA) whose both transition coupled to the guided modes of a one-dimensional (1D) waveguide at two spatially separated points with the GA initially excited and the electromagnetic (EM) modes of waveguide in vacuum. The spontaneous emission properties of this GA is investigated by solving the delay-differential equation for the amplitude of the 3GA in its excited state. Signatures of non-Markovian behavior is manifested in a population trapping in the excited state of the GA in the regime where the distance ddd of the coupling points is smaller or comparable to the coherent length LLL characterizing the width of the emitted wave packet. And an exact Markovian dynamics is also found when d≥Ld\geq Ld≥L via the inference by adjusting the energy spacing and the inherent time delay besides the complex phases in the atom-light coupling, matching the behavior of a small atom coupled to a waveguide.
Emergent Oscillating bound states in a semi-infinite linear waveguide with a point-like ΛΛΛ-type quantum emitter driven by a classical field
An oscillating bound state is a phenomenon where excitations mediated by the continuum modes oscillate persistently. Although it is generated by the superposition of two bound states in the continuum (BICs), such phenomenon is said to be unique to giant atoms. We present the phenomenon of an oscillating bound state with an alternative waveguide QED system, which is a one-dimensional semi-infinite waveguide coupled to a \textit{point-like} quantum emitter. This \textit{point-like} quantum emitter is ΛΛΛ-type quantum system with one transition driven by a classical field.
Abstract We investigate the dynamics of two two-level giant atoms coupled to a one-dimensional waveguide in separate and braided configurations. Using the resolvent method, the quantum dynamics are determined by the poles of the Green’s function. We identify conditions under which three real poles with distinct eigenfrequencies emerge, corresponding to three bound states in the continuum (BICs). Their superposition gives rise to oscillating BICs. In this regime, the atomic excitation oscillates between the two atoms, while the photon field remains confined between the coupling points and exhibits persistent oscillations. The maxima of the photon field distribution coincide with those of the atomic excitations, reflecting the atom-photon bound-state nature. The revival of the photon distribution reveals the coherent interaction between the two giant atoms mediated by the BICs. This work broadens the fields of quantum information storage and manipulation by leveraging larger Hilbert spaces enabled by multiple nonradiative BICs.
Emergent Oscillating Bound States in a Semi‐Infinite Linear Waveguide with a Point‐Like ΛΛ\LambdaΛ‐Type Quantum Emitter Driven by a Classical Field
Abstract An oscillating bound state is a phenomenon where excitations mediated by the continuum modes oscillate persistently. Although it is generated by the superposition of two bound states in the continuum (BICs), such phenomenon is said to be unique to giant atoms. The phenomenon of an oscillating bound state with an alternative waveguide QED system is presented, which is a one dimensional (1D) semi‐infinite waveguide coupled to a point‐like quantum emitter. This point‐like quantum emitter is ‐type quantum system with one transition driven by a classical field.
Waveguide quantum electrodynamics platforms have emerged as promising candidates for exploring and implementing non-Markovian quantum phenomena. In this work, we investigate the formation and dynamics of superpositions of bound states in a cavity array waveguide coupled to two spatially separated quantum emitters. By tuning the system parameters, we show that spontaneous emission can drive the system into non-local equilibrium states in which both photonic and emitter populations exhibit persistent oscillations. These states arise from the coexistence of bound states embedded in the energy continuum and bound states outside it, leading to hybrid oscillatory modes. We analytically derive the conditions required for the emergence of these states, numerically simulate their formation through spontaneous emission, and predict their long-time behaviour. Our results demonstrate that such bound-state superpositions enable the generation of emitter-emitter interaction through free evolution, while supporting oscillatory breathing modes of the photon density between the emitters.