Route from spontaneous decay to complex multimode dynamics in cavity QED

Krimer, Dmitry O.; Liertzer, Matthias; Rotter, Stefan; Türeci, Hakan E.

doi:10.1103/physreva.89.033820

Cited by 41 publications

(47 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the focus in the spin-boson problem is on the ensuing strong spin-bath correlations [7,14], in the MMSC regime the focus is on the resulting complex temporal dynamics of the bosonic degrees of freedom. It was pointed out [8] that the quench dynamics in this regime feature pulsed emission characterized by the cavity round-trip time, instead of Purcell modified pure exponential decay or damped Rabi oscillations characterizing the single-cavity-mode problem. Driving such a system is hence expected to lead to an entirely new quantum dynamical regime that may feature frequency correlations that are unique to the multimode nature of the coupling.…”

mentioning

confidence: 99%

“…Here, we investigate multimode strong coupling (MMSC) [7,8], where the coupling is comparable to the free spectral range (FSR) of the cavity; i.e., the rate at which a qubit can absorb a photon from the cavity is comparable to the roundtrip transit rate of a photon in the cavity. We realize, via the circuit QED architecture, an experiment accessing the MMSC regime and report remarkably widespread and highly structured resonance fluorescence.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Beyond Strong Coupling in a Multimode Cavity

et al. 2015

Self Cite

View full text Add to dashboard Cite

Here, we report an experimental realization of multimode strong coupling in cavity quantum electrodynamics. This novel regime is achieved when a single artificial atom is simultaneously strongly coupled to a large, but discrete, number of nondegenerate photonic modes of a cavity with coupling strengths comparable to the free spectral range. Our experiment reveals complex quantum multimode dynamics and spontaneous generation of quantum coherence, as evidenced by resonance fluorescence spanning many modes and ultranarrow linewidth emission. This work opens a new avenue for future experiments in light-matter interactions and poses a challenge to current theoretical approaches to its study. DOI: 10.1103/PhysRevX.5.021035 Subject Areas: Condensed Matter Physics, Photonics, Quantum PhysicsThe study of light-matter interaction has seen a resurgence in recent years, stimulated by highly controllable, precise, and modular experiments in cavity quantum electrodynamics (QED) [1]. The achievement of strong coupling [2][3][4], where the coupling between a single atom and fundamental cavity mode exceeds the decay rates, was a major milestone that opened the doors to a multitude of new investigations [5,6].Here, we investigate multimode strong coupling (MMSC) [7,8], where the coupling is comparable to the free spectral range (FSR) of the cavity; i.e., the rate at which a qubit can absorb a photon from the cavity is comparable to the roundtrip transit rate of a photon in the cavity. We realize, via the circuit QED architecture, an experiment accessing the MMSC regime and report remarkably widespread and highly structured resonance fluorescence. The observed drive dependence of the width, height, and position of the fluorescence peaks cannot be explained by cavity enhancement of sidebands observed in the single-mode regime [9]. As expounded below, our observations reveal a generation of coherence across multiple frequencies mediated by a single qubit and necessitate a multimode analysis. Beyond the novel phenomena presented here, the access to the MMSC regime opens up a new direction of exploration that is of interest both theoretically and experimentally.Interest in going beyond strong coupling has focused on the ultrastrong-coupling limit, where the breakdown of the rotating-wave approximation for the light-matter interaction results in excitation nonconserving terms [10][11][12][13]. In contrast, the direction which we pursue is the simultaneous strong coupling of the qubit to numerous modes, leading to qubit-mediated mode-mode interactions and nonlinear quantum dynamics not present in the single-mode problem. Thus, MMSC demonstrates a qualitatively new domain, intermediate between the quantum mechanics of systems with a small number of degrees of freedom and full continuum quantum field theory in free space. Unlike the traditional spin-boson problem that involves a bosonic continuum with an algebraic bath spectral function of the type JðωÞ ¼ αω s , the MMSC regime is described by a structured spectral function with an infi...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Beyond Strong Coupling in a Multimode Cavity

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

“…So far, this has only been realized in the microwave domain [23]. Multimode strong coupling enables atom-mediated interactions between different optical modes and results in a nonlinear quantum dynamics that is not present in the single-mode regime [18]. Atom-mediated mode coupling has recently also been considered for implementing photonic quantum simulation protocols [24].…”

mentioning

confidence: 99%

“…Finally, the optical path length of such a tapered fiber ring (TFR) resonator can be significantly increased without reducing its cooperativity. This makes this system a prime candidate for experimentally exploring the regime of optical multimode strong coupling where the atoms simultaneously couple strongly to many longitudinal resonator modes [17,18].Our ring resonator consists of a tapered optical fiber with a nanofiber waist connected to an adjustable fiber beam splitter (Newport F-CPL-830-N-FA), see Fig. 1(a), whose splitting ratio can be continuously adjusted between 0 % and 100 %.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Fiber ring resonator with a nanofiber section for chiral cavity quantum electrodynamics and multimode strong coupling

Schneeweiß¹,

Zeiger²,

Hoinkes³

et al. 2016

Opt. Lett.

View full text Add to dashboard Cite

We experimentally realize an optical fiber ring resonator that includes a tapered section with subwavelength-diameter waist. In this section, the guided light exhibits a significant evanescent field which allows for efficient interfacing with optical emitters. A commercial tunable fiber beam splitter provides simple and robust coupling to the resonator. Key parameters of the resonator such as its out-coupling rate, free spectral range, and birefringence can be adjusted. Thanks to the low taperand coupling-losses, the resonator exhibits an unloaded finesse of F = 75 ± 1, sufficient for reaching the regime of strong coupling for emitters placed in the evanescent field. The system is ideally suited for trapping ensembles of laser-cooled atoms along the nanofiber section. Based on measured parameters, we estimate that the system can serve as a platform for optical multimode strong coupling experiments. Finally, we discuss the possibilities of using the resonator for applications based on chiral quantum optics.Over the past years, significant research effort has been devoted to interfacing quantum emitters, such as molecules, quantum dots, color centers, and neutral atoms, with fiber-guided light fields. Suitable lightmatter interfaces are considered to be key elements for future quantum networks [1]. One way to realize such an interface consists in coupling emitters to the evanescent fields surrounding the nanofiber-waist of a tapered optical fiber, i.e., a fiber section with sub-wavelength diameter. Such systems already provide absorption probabilities for single fiber-guided photons of about 25 % for a single emitter located on the nanofiber surface [2] and about 5 % at a distance of 200 nm, typical for cold atoms in nanofiber-based optical dipole traps [3,4].One way to further enhance the light-matter coupling strength is to increase the number of emitters in the evanescent field and to take advantage of their collective coupling. Another option relies on confining the light in an optical resonator, which allows one to even reach the regime of strong coupling in the sense of cavity quantum electrodynamics (CQED) [5]. There, coherent emitterlight interaction strength dominates over the incoherent decay channels. In this context, optical nanofibers are a versatile platform as they allow one to combine both approaches and, in this way, to reach very strong lightmatter coupling in an fiber-integrated environment.Different nanofiber-based Fabry-Pérot resonator schemes have been developed, e.g., based on Bragg structures created using ion beam milling [6] Here, we demonstrate a tapered fiber-based ring resonator with optical characteristics that are compatible with entering the regime of single-atom strong coupling. We experimentally reach a resonator finesse of F = 75 ± 1 which corresponds to a single-atom cooperativity of C ≈ 1. Our implementation offers easy tuning of the resonator eigenpolarizations and out-coupling rate as well as straightforward adjustment of the resonator's free spectral range. Our system is co...

show abstract

Room‐Temperature Quantum Memories Based on Molecular Electron Spin Ensembles

et al. 2021

View full text Add to dashboard Cite

Superconducting quantum bits are addressed by means of microwave radiation and quantum memories in this context thus need to be able to store microwave photon states. To this end, resonant structures for electromagnetic radiation can be used to strongly couple quantum bits and quantum memories to quantized cavity modes of the electromagnetic field. The strong coupling generates a hybrid quantum system that allows mapping the qubit state onto the cavity field state. [6] This strategy has given rise to the field of cavity quantum electrodynamics and has already been used to couple two superconducting qubits together via a cavity bus. [7] A second application of quantum memories is in quantum repeaters for quantum communication. Because telecom wavelengths are in the near-infrared, for this application, optical quantum memories are required that store optical photon states. [8] Considering the choice of material platform for designing microwave quantum memories, electron spins in solids can be easily addressed by microwave pulses and have been shown to possess excellent coherence times up to seconds, for some systems even up to room temperature. [9][10] Unfortunately, the coupling of a single electron spin to a photon is very weak. Although resonant structures can be tailored to improve single-spin coupling, [11][12][13] the weakness of the coupling renders addressing individual spins by means of coupling to cavity modes very challenging. This can be overcome by using an electron spin ensemble rather than single spins, because the coupling strength of a spin ensemble to an electromagnetic resonator mode is proportional to the square root of the number of electron spins in the ensemble. [14] This then leads to the general idea of the implementation of a microwave quantum memory using spin ensembles and microwave resonators (Figure 1). The state to be stored is encoded in a weak microwave pulse and sent to the hybrid quantum system constituted of an electron spin ensemble that is strongly coupled to a microwave resonator, where it is stored. When the quantum state is needed again, a strong microwave pulse is sent to the resonator, which leads to deterministic retrieval of the quantum state that is emitted as a microwave photon to be used as desired.Strong coupling between cavity and electron spin ensembles has been observed in a variety of spin systems, including organic radicals, [15][16][17][18][19][20] phosphorous dopants in silicon, [21,22] P1 and nitrogen vacancy (NV) defects in diamond, [23][24][25][26][27][28][29][30][31][32] N@ C 60 , [33] rare earth dopants in oxides, [34,35] transition metal Whilst quantum computing has recently taken great leaps ahead, the development of quantum memories has decidedly lagged behind. Quantum memories are essential devices in the quantum technology palette and are needed for intermediate storage of quantum bit states and as quantum repeaters in long-distance quantum communication. Current quantum memories operate at cryogenic, mostly sub-Kelvin temperatures and require extens...

show abstract

Route from spontaneous decay to complex multimode dynamics in cavity QED

Cited by 41 publications

References 39 publications

Beyond Strong Coupling in a Multimode Cavity

Beyond Strong Coupling in a Multimode Cavity

Fiber ring resonator with a nanofiber section for chiral cavity quantum electrodynamics and multimode strong coupling

Room‐Temperature Quantum Memories Based on Molecular Electron Spin Ensembles

Contact Info

Product

Resources

About