Magnetic control of Coulomb scattering and terahertz transitions among excitons

Bhattacharyya, Jayeeta; Zybell, S.; Eßer, F.; Helm, M.; Schneider, Harald; Schneebeli, L.; Böttge, C. N.; Breddermann, B.; Kira, M.; Koch, S. W.; Andrews, A. M.; Strasser, G.

doi:10.1103/physrevb.89.125313

Cited by 6 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both contributions exhibit resonances at the exciton energy E µ . For an EI with s-symmetric ground state the first excited exciton is of p-symmetry, that we can expect the 1s-2p transition as the energetically lowest resonance 39,40 . For a p-excited state (µ = p in Eq.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Excitonic insulator states in molecular functionalized atomically-thin semiconductors

Christiansen¹,

Selig²,

Rossi³

et al. 2021

Preprint

View full text Add to dashboard Cite

The excitonic insulator is an elusive electronic phase exhibiting a correlated excitonic ground state. Materials with such a phase are expected to have intriguing properties such as excitonic high-temperature superconductivity. However, compelling evidence on the experimental realization is still missing. Here, we theoretically propose hybrids of two-dimensional semiconductors functionalized by organic molecules as prototypes of excitonic insulators, with the exemplary candidate WS2-F6TCNNQ. This material system exhibits an excitonic insulating phase at room temperature with a ground state formed by a condensate of interlayer excitons. To address an experimentally relevant situation, we calculate the corresponding phase diagram for the important parameters: temperature, gap energy, and dielectric environment. Further, to guide future experimental detection, we show how to optically characterize the different electronic phases via far-infrared to terahertz (THz) spectroscopy.

show abstract

Section: Introductionmentioning

confidence: 99%

“…1(d), occurs if the expected exciton binding energy is larger than the band gap. We will exploit that the farinfrared response of such EIs are characterized by transitions in the exciton ladder 39,40 of condensed ground state excitons to higher bound states.…”

Section: Introductionmentioning

confidence: 99%

Excitonic insulator states in molecular functionalized atomically-thin semiconductors

Christiansen¹,

Selig²,

Rossi³

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…[8][9][10] As a way of reflecting the interaction between THz pulse and electrons, photoluminescence (PL) has attracted wide attention. [13][14][15][16][17][18][19] For instance, the THz-induced photoluminescence quenching phenomenon is observed by using the terahertz wave as a quenching source and the femtosecond laser with a wavelength of 800 nm as an excitation source. [14,19] Liu et al in 2010 observed the PLQ phenomenon of CdTe and GaAs from single-cycle THz pulse by using the time-integrated PL spectra measurement.…”

Section: Introductionmentioning

confidence: 99%

Linear and nonlinear characteristics of time-resolved photoluminescence modulation by terahertz pulse

Gong¹,

Liu²,

Zhang³

et al. 2017

Chinese Phys. B

View full text Add to dashboard Cite

The linear and nonlinear characteristics of time-resolved photoluminescence (PL) of n-type bulk semiconductor GaAs modulated with terahertz (THz) pulse are studied by using an ensemble Monte Carlo (EMC) method. In this paper the center energy valley (Γ valley) electron concentration changes with the pulse delay time, sampling time and the outfield are mainly discussed. The results show that the sampling time and the THz field should exceed certain thresholds to effectively excite photoluminescence quenching (PLQ). Adopting a direct current (DC) field makes the sampling time threshold shortened and the linear range of THz field-modulation PL expanded. Moreover, controlling the sampling time and the outfield intensity can improve the linear quality: with forward time, the larger outfield is used; with backward time, the smaller outfield is used. This study can provide a theoretical basis of THz field linear modulation in a larger range for new light emitting devices.

show abstract

“…The internal states of an exciton, which are analogous to the states of a hydrogen atom, can be probed by intraexciton transitions (i.e., the excitonic Lyman or Balmer series) using terahertz (THz) radiation (meV in photon energy) . These transitions evolve as a function of B, exhibiting shifts and splittings [1,12,17,20,23], which provide insight into dark states that are not observable in interband optical experiments. It has been recently shown, by probing the 1s − 2p − transition [20], that two-dimensional (2D) magnetoexcitons in high B are extremely stable against an excitonic Mott transition [24][25][26][27][28][29][30], which would ordinarily transform the system from an insulating and bosonic exciton gas into a metallic and fermionic e-h plasma at high pair densities.…”

mentioning

confidence: 99%

Observation of Photoinduced Terahertz Gain in GaAs Quantum Wells: Evidence for Radiative Two-Exciton-to-Biexciton Scattering

Yoshioka

Zhang

et al. 2020

Phys. Rev. Lett.

View full text Add to dashboard Cite

We have observed photoinduced negative optical conductivity, or gain, in the terahertz frequency range in a GaAs multiple-quantum-well structure in a strong perpendicular magnetic field at low temperatures. The gain is narrow band: it appears as a sharp peak (linewidth < 0.45 meV) whose frequency shifts with applied magnetic field. The gain has a circular-polarization selection rule: a strong line is observed for holecyclotron-resonance-active polarization. Furthermore, the gain appears only when the exciton 1s state is populated, which rules out intraexcitonic transitions to be its origin. Based on these observations, we propose a possible process in which the stimulated emission of a terahertz photon occurs while two free excitons scatter into one biexciton in an energy and angular-momentum conserving manner.

show abstract

Magnetic control of Coulomb scattering and terahertz transitions among excitons

Cited by 6 publications

References 33 publications

Excitonic insulator states in molecular functionalized atomically-thin semiconductors

Excitonic insulator states in molecular functionalized atomically-thin semiconductors

Linear and nonlinear characteristics of time-resolved photoluminescence modulation by terahertz pulse

Observation of Photoinduced Terahertz Gain in GaAs Quantum Wells: Evidence for Radiative Two-Exciton-to-Biexciton Scattering

Contact Info

Product

Resources

About