Measurement of cyclotron resonance relaxation time in the two-dimensional electron system

Andreev, I. V.; Muravev, V. M.; Belyanin, V. N.; Кукушкин, И. В.

doi:10.1063/1.4902133

Cited by 30 publications

(12 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Especially in the strong light-matter coupling regime, the reversible emission/absorption leads to the exchange of energy between light and matter, and thus, the radiation decay is suppressed. Experimentally, such a situation has been achieved by strongly coupling CR to plasmons [168] or cavity photons [169].…”

Section: Observation Of Superradiant Decay Of Crmentioning

confidence: 99%

Dicke superradiance in solids [Invited]

et al. 2016

View full text Add to dashboard Cite

Recent advances in optical studies of condensed matter systems have led to the emergence of a variety of phenomena that have conventionally been studied in the realm of quantum optics. These studies have not only deepened our understanding of light-matter interactions but also introduced aspects of many-body correlations inherent in optical processes in condensed matter systems. This article is concerned with the phenomenon of superradiance (SR), a profound quantum optical process originally predicted by Dicke in 1954. The basic concept of SR applies to a general N -body system where constituent oscillating dipoles couple together through interaction with a common light field and accelerate the radiative decay of the whole system. Hence, the term SR ubiquitously appears in order to describe radiative coupling of an arbitrary number of oscillators in many situations in modern science of both classical and quantum description. In the most fascinating manifestation of SR, known as superfluorescence (SF), an incoherently prepared system of N inverted atoms spontaneously develops macroscopic coherence from vacuum fluctuations and produces a delayed pulse of coherent light whose peak intensity ∝ N 2 . Such SF pulses have been observed in atomic and molecular gases, and their intriguing quantum nature has been unambiguously demonstrated. In this review, we focus on the rapidly developing field of research on SR phenomena in solids, where not only photon-mediated coupling (as in atoms) but also strong Coulomb interactions and ultrafast scattering processes exist. We describe SR and SF in molecular centers in solids, molecular aggregates and crystals, quantum dots, and quantum wells. In particular, we will summarize a series of studies we have recently performed on semiconductor quantum wells in the presence of a strong magnetic field. In one type of experiment, electron-hole pairs were incoherently prepared, but a macroscopic polarization spontaneously emerged and cooperatively decayed, emitting an intense SF burst. In another type of experiment, we observed the SR decay of coherent cyclotron resonance of ultrahigh-mobility two-dimensional electron gases, leading to a decay rate that is proportional to the electron density. These results show that cooperative effects in solid-state systems are not merely small corrections that require exotic conditions to be observed; rather, they can dominate the nonequilibrium dynamics and light emission processes of the entire system of interacting electrons.

show abstract

Section: Observation Of Superradiant Decay Of Crmentioning

confidence: 99%

Dicke superradiance in solids [Invited]

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Considering that the condition d > λ is already fulfilled at 110 GHz, we interpret the broad envelope resonance as a pure CR with width defined by a collective superradiant relaxation ∆ω = Γ (see Eqs. 3-4), whereas the magnetoplasma resonance linewidth is determined by a single-particle collisional relaxation, ∆ω = 1/τ [22]. Therefore, the magnetoplasma resonances are superimposed on the CR contour forming a fine structure of the resonance.…”

mentioning

confidence: 99%

“…The magnetoplasma mode width saturates at a constant level of ∆f = 1 GHz in the low-frequency limit. We attribute the relaxation of the plasma mode in this limit to incoherent scattering of charged carriers in the 2DES, ∆ω = γ = 1/τ [22], where γ is the incoherent collisional scattering rate in the sample. As the magnetoplasmon frequency is increased to c/nf ∼ d, the mode width rises rapidly.…”

mentioning

confidence: 99%

Fine structure of cyclotron resonance in a two-dimensional electron system

et al. 2016

Self Cite

View full text Add to dashboard Cite

It is established that cyclotron resonance (CR) in a high-quality GaAs/AlGaAs two-dimensional electron system (2DES) originates as a pure resonance, that does not hybridize with dimensional magnetoplasma excitations. The magnetoplasma resonances form a fine structure of the CR. The observed fine structure of the CR results from the interplay between coherent radiative and incoherent collisional mechanisms of 2D plasma relaxation. We show that the range of 2DES filling factors from which the phenomenon arises is intimately connected to the fundamental fine-structure constant.Cyclotron resonance (CR) spectroscopy is the most direct and convenient method of characterizing the Fermi surface and determining the effective mass of semiconductors [1][2][3]. In a two-dimensional electron system (2DES), a perpendicular magnetic field quenches the inplane motion of electrons into cyclotron orbits. In turn, if the phase and polarization of the incident electromagnetic radiation are synchronized with the electron orbital motion, CR is triggered. The first observation of CR in 2DESs was reported for charged carriers in an inversion layer on Si [4, 5]. Subsequently, CR spectroscopy has been successfully applied to research on many two-dimensional systems, for example, isotropic 2D carriers in GaAs heterostructures [6][7][8], composite fermions [9], heavy fermions in MgZnO/ZnO heterojunctions [10,11], and anisotropic heavy fermions in AlAs quantum wells [12,13].It is widely believed that the cyclotron resonance originates from the dimensional magnetoplasma resonance [15,16,20]. The frequency of the hybrid cyclotron magnetoplasma mode is described by the equationwhere ω c = eB/m * c is the cyclotron frequency, and ω p is the dimensional plasmon frequency [17] (Gaussian units are used in this Letter unless otherwise stated):Here, n s and m * are the density and the effective mass of the 2D electrons, and ε is the effective permittivity of the surrounding medium. For a narrow 2DES stripe of width W , the plasmon wavevector can be approximately described by q = πN/W (N = 1, 2, . . . is the number of the plasmon harmonic).Contrary to general believe, we discovered that the CR originates as a pure resonance, that does not hybridize with dimensional magnetoplasma excitations. The CR rises as a single peak with superimposed contribution from different dimensional magnetoplasma modes. Therefore, initially the CR line shape exhibits a multipeak structure. We show that the CR fine structure is resolved when the coherent radiative 2D plasma relaxation dominates the incoherent collisional damping. In large samples, this regime appears when the 2D conductivity 2πσ xx is much larger than c. Moreover, the range of 2DES filling factors ν in which the CR fine structure necessarily arises is dictated by the relation 2πσ xy > c. The latter can be rewritten very elegantly as ν > 1/α, where α = e 2 / c ≈ 1/137 is the fundamental fine-structure constant.Experiments were performed on a set of high-quality GaAs/AlGaAs single quantum wells with a well w...

show abstract

“…At 2 K, τ CR is still lower than τ DC . How the CR linewidth in a high-mobility 2DEG changes with the magnetic field and temperature is a long-standing question [30], and a systematic study of 'superradiancefree' CR widths should provide significant new insight.…”

mentioning

confidence: 99%

Collective non-perturbative coupling of 2D electrons with high-quality-factor terahertz cavity photons

et al. 2016

View full text Add to dashboard Cite

Nonperturbative coupling of light with condensed matter in an optical cavity is expected to reveal a host of coherent many-body phenomena and states [1][2][3][4][5][6][7]. In addition, strong coherent light-matter interaction in a solid-state environment is of great interest to emerging quantum-based technologies [8,9]. However, creating a system that combines a long electronic coherence time, a large dipole moment, and a high cavity quality (Q) factor has been a challenging goal [10][11][12][13]. Here, we report collective ultrastrong light-matter coupling in an ultrahigh-mobility two-dimensional electron gas in a high-Q terahertz photonic-crystal cavity in a quantizing magnetic field, demonstrating a cooperativity of ∼360. The splitting of cyclotron resonance (CR) into the lower and upper polariton branches exhibited a √ ne-dependence on the electron density (ne), a hallmark of collective vacuum Rabi splitting. Furthermore, a small but definite blue shift was observed for the polariton frequencies due to the normally negligible A 2 term in the light-matter interaction Hamiltonian. Finally, the high-Q cavity suppressed the superradiant decay of coherent CR, which resulted in an unprecedentedly narrow intrinsic CR linewidth of 5.6 GHz at 2 K. These results open up a variety of new possibilities to combine the traditional disciplines of many-body condensed matter physics and cavity-based quantum optics.PACS numbers: 78.67. De, 76.40.+b, 78.47.jh Strong resonant light-matter coupling in a cavity setting is an essential ingredient in fundamental cavity quantum electrodynamics (QED) studies [14] as well as in cavity-QED-based quantum information processing [8,9]. In particular, a variety of solid-state cavity QED systems have recently been examined [15][16][17][18], not only for the purpose of developing scalable quantum technologies, but also for exploring novel many-body effects inherent to condensed matter. For example, collective √ N -fold enhancement of light-matter coupling in an N -body system [19], combined with colossal dipole moments available in solids, compared to traditional atomic systems, is promising for entering uncharted regimes of ultrastrong light-matter coupling. Nonintuitive quantum phenomena can occur in such regimes, including a "squeezed" vacuum state [1], the Dicke superradiant phase transition [2,3], the breakdown of the Purcell effect [4], and quantum vacuum radiation [5] induced by the dynamic Casimir effect [6,7].Specifically, in a cavity QED system, there are three rates that jointly characterize different light-matter coupling regimes: g, κ, and γ. The parameter g is the coupling constant, with 2g being the vacuum Rabi splitting between the two normal modes, the lower polariton (LP) and upper polariton (UP), of the coupled system. The parameter κ is the photon decay rate of the cavity; τ cav = κ −1 is the photon lifetime of the cavity, and the cavity Q = ω 0 τ cav at mode frequency ω 0 . The parameter γ is the nonresonant matter decay rate, which is usually the decoherence rate in ...

show abstract

Measurement of cyclotron resonance relaxation time in the two-dimensional electron system

Cited by 30 publications

References 24 publications

Dicke superradiance in solids [Invited]

Dicke superradiance in solids [Invited]

Fine structure of cyclotron resonance in a two-dimensional electron system

Collective non-perturbative coupling of 2D electrons with high-quality-factor terahertz cavity photons

Contact Info

Product

Resources

About