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Anders D, Dobener F, Schäfer F, Chatterjee S, Stein M. Inhibited Inelastic Scattering of Incoherent Excitons for Near-Band Edge Excitations. PHYSICAL REVIEW LETTERS 2024; 132:106901. [PMID: 38518321 DOI: 10.1103/physrevlett.132.106901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 02/12/2024] [Indexed: 03/24/2024]
Abstract
A multiple pump-terahertz probe experiment enables the clear distinction between elastic and inelastic scattering of excitons with a free electron-hole plasma in (Ga,In)As multiquantum wells. Low plasma energies dictate the prevalence of elastic scattering by inhibiting inelastic processes due to the absence of final states for quasiparticles. Yet, an increased plasma energy results in a progressive destruction of excitons. Notably, despite plasma energy variations, the interaction strength between excitons and the electron-hole plasma remains unaltered.
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Affiliation(s)
- D Anders
- Institute of Experimental Physics I and Center for Materials Research (LaMa), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - F Dobener
- Institute of Experimental Physics I and Center for Materials Research (LaMa), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - F Schäfer
- Institute of Experimental Physics I and Center for Materials Research (LaMa), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - S Chatterjee
- Institute of Experimental Physics I and Center for Materials Research (LaMa), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - M Stein
- Institute of Experimental Physics I and Center for Materials Research (LaMa), Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
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Scharf B, Van Tuan D, Žutić I, Dery H. Dynamical screening in monolayer transition-metal dichalcogenides and its manifestations in the exciton spectrum. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:203001. [PMID: 30763925 DOI: 10.1088/1361-648x/ab071f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Monolayer transition-metal dichalcogenides (ML-TMDs) offer exciting opportunities to test the manifestations of many-body interactions through changes in the charge density. The two-dimensional character and reduced screening in ML-TMDs lead to the formation of neutral and charged excitons with binding energies orders of magnitude larger than those in conventional bulk semiconductors. Tuning the charge density by a gate voltage leads to profound changes in the optical spectra of excitons in ML-TMDs. On the one hand, the increased screening at large charge densities should result in a blueshift of the exciton spectral lines due to reduction in the binding energy. On the other hand, exchange and correlation effects that shrink the band-gap energy at elevated charge densities (band-gap renormalization) should result in a redshift of the exciton spectral lines. While these competing effects can be captured through various approximations that model long-wavelength charge excitations in the Bethe-Salpeter equation, we show that a novel coupling between excitons and shortwave charge excitations is essential to resolve several experimental puzzles. Unlike ubiquitous and well-studied plasmons, driven by collective oscillations of the background charge density in the long-wavelength limit, we discuss the emergence of shortwave plasmons that originate from the short-range Coulomb interaction through which electrons transition between the [Formula: see text] and [Formula: see text] valleys. The shortwave plasmons have a finite energy-gap because of the removal of spin-degeneracy in both the valence- and conduction-band valleys (a consequence of breaking of inversion symmetry in combination with strong spin-orbit coupling in ML-TMDs). We study the coupling between the shortwave plasmons and the neutral exciton through the self-energy of the latter. We then elucidate how this coupling as well as the spin ordering in the conduction band give rise to an experimentally observed optical sideband in electron-doped W-based MLs, conspicuously absent in electron-doped Mo-based MLs or any hole-doped ML-TMDs. While the focus of this review is on the optical manifestations of many-body effects in ML-TMDs, a systematic description of the dynamical screening and its various approximations allow one to revisit other phenomena, such as nonequilibrium transport or superconducting pairing, where the use of the Bethe-Salpeter equation or the emergence of shortwave plasmons can play an important role.
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Affiliation(s)
- Benedikt Scharf
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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Ferreira AC, Holtz PO, Sernelius BE, Buyanova I, Monemar B, Mauritz O, Ekenberg U, Sundaram M, Campman K, Merz JL, Gossard AC. Exciton properties in p-type GaAs/AlxGa1-xAs quantum wells in the high doping regime. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:16989-16993. [PMID: 9985829 DOI: 10.1103/physrevb.54.16989] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Brown SA, Young JF, Brum JA, Hawrylak P, Wasilewski Z. Evolution of the interband absorption threshold with the density of a two-dimensional electron gas. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:R11082-R11085. [PMID: 9984991 DOI: 10.1103/physrevb.54.r11082] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Harel R, Cohen E, Linder E, Ron A, Pfeiffer LN. Absolute transmission, reflection, and absorption studies in GaAs/AlAs quantum wells containing a photoexcited electron gas. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:7868-7875. [PMID: 9982237 DOI: 10.1103/physrevb.53.7868] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Godlewski M, Lundström T, Zhao QX, Chen WM, Holtz PO, Monemar B, Anderson TG. Optically detected cyclotron-resonance studies of radiative processes in AlxGa1-xAs/GaAs high-electron-mobility structures. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:14688-14692. [PMID: 9980804 DOI: 10.1103/physrevb.52.14688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Amand T, Dareys B, Baylac B, Marie X, Barrau J, Brousseau M, Dunstan DJ, Planel R. Exciton formation and hole-spin relaxation in intrinsic quantum wells. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:11624-11628. [PMID: 9975295 DOI: 10.1103/physrevb.50.11624] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Gumbs G, Huang D, Yin Y, Qiang H, Yan D, Pollak FH, Noble TF. Many-body effects in the electromodulation spectra of modulation-doped quantum wells: Theory and experiment. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:18328-18331. [PMID: 10008487 DOI: 10.1103/physrevb.48.18328] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Zhao QX, Holtz PO, Monemar B, Lundström T, Wallin J, Landgren G. Electron and hole effective masses from magnetoluminescence studies of modulation-doped InP/In0.53Ga0.47As heterostructures. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:11890-11896. [PMID: 10007530 DOI: 10.1103/physrevb.48.11890] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Harris CI, Monemar B, Kalt H, Köhler K. Doping-density dependence of photoluminescence in highly Si-doped GaAs/AlxGa1-xAs quantum wells from below to above the metallic limit. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:4687-4694. [PMID: 10008953 DOI: 10.1103/physrevb.48.4687] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Garini Y, Ehrenfreund E, Cohen E, Ron A, Law K, Merz JL, Gossard AC. Optically induced intersubband absorption in the presence of a two-dimensional electron gas in quantum wells. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:4456-4459. [PMID: 10008921 DOI: 10.1103/physrevb.48.4456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Yoon HW, Wake DR, Wolfe JP, Morkoç H. In-plane transport of photoexcited carriers in GaAs quantum wells. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:13461-13470. [PMID: 10003393 DOI: 10.1103/physrevb.46.13461] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Schlaad K, Weber C, Cunningham J, Hoof CV, Borghs G, Weimann G, Schlapp W, Nickel H, Klingshirn C. Many-particle effects and nonlinear optical properties of GaAs/(Al,Ga)As multiple-quantum-well structures under quasistationary excitation conditions. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:4268-4275. [PMID: 9997778 DOI: 10.1103/physrevb.43.4268] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Huang D, Chyi JI, Morkoç H. Carrier effects on the excitonic absorption in GaAs quantum-well structures: Phase-space filling. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:5147-5153. [PMID: 9996077 DOI: 10.1103/physrevb.42.5147] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Andrews SR, Plaut AS, Harley RT, Kerr TM. Optical studies of electron and hole Fermi seas in a single GaAs/AlxGa1-xAs quantum well. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 41:5040-5047. [PMID: 9994360 DOI: 10.1103/physrevb.41.5040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Honold A, Schultheis L, Kuhl J, Tu CW. Collision broadening of two-dimensional excitons in a GaAs single quantum well. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:6442-6445. [PMID: 9992726 DOI: 10.1103/physrevb.40.6442] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Theis WM, Sanders GD, Evans KR, Liou LL, Leak CE, Bajaj KK, Stutz CE, Jones RL, Chang YC. Extrinsic contributions to photoreflectance of AlxGa1-xAs/GaAs quantum wells: An investigation of the "donor-related" feature. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:11038-11043. [PMID: 9947918 DOI: 10.1103/physrevb.39.11038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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