Inducing room-temperature valley polarization of excitonic emission in transition metal dichalcogenide monolayers

• URL: http://arxiv.org/abs/2308.10514v1
• Date: Mon, 21 Aug 2023 07:01:39 GMT
• Title: Inducing room-temperature valley polarization of excitonic emission in transition metal dichalcogenide monolayers
• Authors: Sergii Morozov, Torgom Yezekyan, Christian Wolff, Sergey I. Bozhevolnyi, N. Asger Mortensen
• Abstract summary: We show that strong doping levels beyond $1013$cm$-2$ can induce 61% and 37% valley contrast at room temperature in TMD monolayers. Our results indicate that charged excitons in TMD monolayers can be utilized as quantum units in designing of practical valleytronic devices operating at 300 K.
• Score: 0.929965561686354
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The lowest energy states in transition metal dichalcogenide (TMD) monolayers follow valley selection rules, which have attracted vast interest due to the possibility of encoding and processing of quantum information. However, these quantum states are strongly affected by the temperature-dependent intervalley scattering causing complete valley depolarization, which is hampering any practical applications of TMD monolayers at room temperature. Therefore, for achieving clear and robust valley polarization in TMD monolayers one needs to suppress parasitic depolarization processes, which is the central challenge in the growing field of valleytronics. Here, in electron-doping experiments on TMD monolayers, we demonstrate that strong doping levels beyond $10^{13}$~cm$^{-2}$ can induce 61\% and 37\% valley contrast at room temperature in tungsten diselenide and molybdenum diselenide monolayers, respectively. Our results indicate that charged excitons in TMD monolayers can be utilized as quantum units in designing of practical valleytronic devices operating at 300 K.

Related papers

• Site-Controlled Purcell-Induced Bright Single Photon Emitters in Hexagonal Boron Nitride [62.170141783047974]
  Single photon emitters hosted in hexagonal boron nitride (hBN) are essential building blocks for quantum photonic technologies that operate at room temperature. We experimentally demonstrate large-area arrays of plasmonic nanoresonators for Purcell-induced site-controlled SPEs. Our results offer arrays of bright, heterogeneously integrated quantum light sources, paving the way for robust and scalable quantum information systems.
  arXiv  Detail & Related papers  (2024-05-03T23:02:30Z)
• Highly tunable room-temperature plexcitons in monolayer WSe2 /gap-plasmon nanocavities [0.0]
  We realize real-time, room-temperature tunable strong plasmon-exciton coupling in 2D semiconductor monolayers. We show that the exciton energy and nanocavity plasmon resonance can be controllably toggled in concert by applying pressure with a plasmonic nanoprobe.
  arXiv  Detail & Related papers  (2023-11-04T21:16:46Z)
• Dynamics of moire trion and its valley polarization in microfabricated WSe2/MoSe2 heterobilayer [0.36944296923226316]
  We propose a microfabrication technique based on focused Ga+ ion beams, which enables us to control the number of peaks originating from the moire potential. By taking advantage of this approach, we reveal emissions from a single moire exciton and charged moire exciton (trion) under electrostatic doping conditions.
  arXiv  Detail & Related papers  (2023-01-26T10:02:37Z)
• On the Su-Schrieffer-Heeger model of electron transport: low-temperature optical conductivity by the Mellin transform [62.997667081978825]
  We describe the low-temperature optical conductivity as a function of frequency for a quantum-mechanical system of electrons that hop along a polymer chain. Our goal is to show vias how the interband conductivity of this system behaves as the smallest energy bandgap tends to close.
  arXiv  Detail & Related papers  (2022-09-26T23:17:39Z)
• Anisotropic superconductivity of niobium based on its response to non-magnetic disorder [0.0]
  Niobium is one of the most studied superconductors, both theoretically and experimentally. In addition to power applications in alloys, pure niobium is used for sensitive magneto-sensing, radio-frequency cavities, and, more recently, as circuit metallization layers in superconducting qubits.
  arXiv  Detail & Related papers  (2022-07-28T22:24:27Z)
• Near-monochromatic tuneable cryogenic niobium electron field emitter [48.7576911714538]
  We describe electron field emission from a monocrystalline, superconducting niobium nanotip at a temperature of 5.9 K. The emitted electron energy spectrum reveals an ultra-narrow distribution down to 16 meV. This source will decrease the impact of lens aberration and enable new modes in low-energy electron microscopy, electron energy loss spectroscopy, and high-resolution vibrational spectroscopy.
  arXiv  Detail & Related papers  (2022-05-11T20:46:21Z)
• Engineering the Radiative Dynamics of Thermalized Excitons with Metal Interfaces [58.720142291102135]
  We analyze the emission properties of excitons in TMDCs near planar metal interfaces. We find suppression or enhancement of emission relative to the point dipole case by several orders of magnitude. nanoscale optical cavities are a viable pathway to generating long-lifetime exciton states in TMDCs.
  arXiv  Detail & Related papers  (2021-10-11T19:40:24Z)
• Proximity-induced spin-polarized magnetocaloric effect in transition metal dichalcogenides [0.0]
  We study proximity-induced magnetocaloric effect on 2D transition metal dichalcogenides. We model this heterostructure using a tight-binding model, incorporating exchange and Rashba fields induced by proximity to EuO.
  arXiv  Detail & Related papers  (2021-08-18T20:08:23Z)
• Observation of ~100% valley-coherent excitons in monolayer MoS2 through giant enhancement of valley coherence time [1.189955933770711]
  In monolayer transition metal dichalcogenide semiconductors, valley coherence degrades rapidly due to a combination of fast scattering and inter-valley exchange interaction. Here we demonstrate fully valley coherent excitons by observing 100% degree of linear polarization in steady state photoluminescence. This is the first report in which the excitons are found to be valley coherent in the entire lifetime in monolayer semiconductors.
  arXiv  Detail & Related papers  (2021-06-07T06:30:12Z)
• Chemical tuning of spin clock transitions in molecular monomers based on nuclear spin-free Ni(II) [52.259804540075514]
  We report the existence of a sizeable quantum tunnelling splitting between the two lowest electronic spin levels of mononuclear Ni complexes. The level anti-crossing, or magnetic clock transition, associated with this gap has been directly monitored by heat capacity experiments. The comparison of these results with those obtained for a Co derivative, for which tunnelling is forbidden by symmetry, shows that the clock transition leads to an effective suppression of intermolecular spin-spin interactions.
  arXiv  Detail & Related papers  (2021-03-04T13:31:40Z)
• Deterministic single-atom source of quasi-superradiant $N$-photon pulses [62.997667081978825]
  Scheme operates with laser and cavity fields detuned from the atomic transition by much more than the excited-state hyperfine splitting. This enables reduction of the dynamics to that of a simple, cavity-damped Tavis-Cummings model with the collective spin determined by the total angular momentum of the ground hyperfine level.
  arXiv  Detail & Related papers  (2020-12-01T03:55:27Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.