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Sun K, Shen K, Gelin MF, Zhao Y. Exciton Dynamics and Time-Resolved Fluorescence in Nanocavity-Integrated Monolayers of Transition-Metal Dichalcogenides. J Phys Chem Lett 2023; 14:221-229. [PMID: 36583951 DOI: 10.1021/acs.jpclett.2c03511] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
We have developed an ab initio-based, fully quantum, numerically accurate methodology for the simulation of the exciton dynamics and time- and frequency-resolved fluorescence spectra of the cavity-controlled two-dimensional materials at finite temperatures and applied this methodology to the single-layer WSe2 system. Specifically, the multiple Davydov D2 Ansatz has been employed in combination with the method of thermofield dynamics for the finite-temperature extension of accurate time-dependent variation. This allowed us to establish dynamical and spectroscopic signatures of the polaronic and polaritonic effects as well as uncover their characteristic time scales in the relevant range of temperatures. Our study reveals the pivotal role of multidimensional conical intersections in controlling the many-body dynamics of highly intertwined excitonic, phononic, and photonic modes.
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Affiliation(s)
- Kewei Sun
- School of Science, Hangzhou Dianzi University, Hangzhou310018, China
| | - Kaijun Shen
- School of Materials Science and Engineering, Nanyang Technological University, Singapore639798, Singapore
| | - Maxim F Gelin
- School of Science, Hangzhou Dianzi University, Hangzhou310018, China
| | - Yang Zhao
- School of Materials Science and Engineering, Nanyang Technological University, Singapore639798, Singapore
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2
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Mosquera MA, Marmolejo-Tejada JM, Borys NJ. Theoretical Quantum Model of Two-Dimensional Propagating Plexcitons. J Chem Phys 2022; 157:124103. [DOI: 10.1063/5.0103383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
When plasmonic excitations of metallic interfaces and nanostructures interact with electronic excitations in semiconductors, new states emerge that hybridize the characteristics of the uncoupled states. The engendered properties make these hybrid states appealing for a broad range of applications, ranging from photovoltaic devices to integrated circuitry for quantum devices. Here, through quantum modeling, the coupling of surface plasmon polaritons and mobile two-dimensional excitons such as those in atomically thin semiconductors is examined with emphasis on the case of strong coupling. Our model shows that at around the energy crossing of the dispersion relationships of the uncoupled species, they strongly interact and polariton states --propagating plexcitons -- emerge. The temporal evolution of the system where surface plasmon polaritons are continuously injected into the system is simulated to gain initial insight on potential experimental realizations of these states. The results show a steady state that is dominated by the lower-energy polariton. The study theoretically further establishes the possible existence of propagating plexcitons in atomically thin semiconductors and provides important guidance for the experimental detection and characterization of such states for a wide range of optoelectronic technologies.
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Affiliation(s)
- Martin Alonso Mosquera
- Department of Chemistry and Biochemistry, Montana State University, United States of America
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3
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Denning EV, Knorr A, Katsch F, Richter M. Efficient Quadrature Squeezing from Biexcitonic Parametric Gain in Atomically Thin Semiconductors. PHYSICAL REVIEW LETTERS 2022; 129:097401. [PMID: 36083637 DOI: 10.1103/physrevlett.129.097401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/17/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Modification of electromagnetic quantum fluctuations in the form of quadrature squeezing is a central quantum resource, which can be generated from nonlinear optical processes. Such a process is facilitated by coherent two-photon excitation of the strongly bound biexciton in atomically thin semiconductors. We show theoretically that interfacing an atomically thin semiconductor with an optical cavity makes it possible to harness this two-photon resonance and use the biexcitonic parametric gain to generate squeezed light with input power an order of magnitude below current state-of-the-art devices with conventional third-order nonlinear materials that rely on far off-resonant nonlinearities. Furthermore, the squeezing bandwidth is found to be in the range of several meV. These results identify atomically thin semiconductors as a promising candidate for on-chip squeezed-light sources.
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Affiliation(s)
- Emil V Denning
- Nichtlineare Optik und Quantenelektronik, Institut für Theoretische Physik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Andreas Knorr
- Nichtlineare Optik und Quantenelektronik, Institut für Theoretische Physik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Florian Katsch
- Nichtlineare Optik und Quantenelektronik, Institut für Theoretische Physik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Marten Richter
- Nichtlineare Optik und Quantenelektronik, Institut für Theoretische Physik, Technische Universität Berlin, 10623 Berlin, Germany
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4
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Trovatello C, Katsch F, Li Q, Zhu X, Knorr A, Cerullo G, Dal Conte S. Disentangling Many-Body Effects in the Coherent Optical Response of 2D Semiconductors. NANO LETTERS 2022; 22:5322-5329. [PMID: 35759746 PMCID: PMC9284612 DOI: 10.1021/acs.nanolett.2c01309] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In single-layer (1L) transition metal dichalcogenides, the reduced Coulomb screening results in strongly bound excitons which dominate the linear and the nonlinear optical response. Despite the large number of studies, a clear understanding on how many-body and Coulomb correlation effects affect the excitonic resonances on a femtosecond time scale is still lacking. Here, we use ultrashort laser pulses to measure the transient optical response of 1L-WS2. In order to disentangle many-body effects, we perform exciton line-shape analysis, and we study its temporal dynamics as a function of the excitation photon energy and fluence. We find that resonant photoexcitation produces a blue shift of the A exciton, while for above-resonance photoexcitation the transient response at the optical bandgap is largely determined by a reduction of the exciton oscillator strength. Microscopic calculations based on excitonic Heisenberg equations of motion quantitatively reproduce the nonlinear absorption of the material and its dependence on excitation conditions.
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Affiliation(s)
- Chiara Trovatello
- Dipartimento
di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Florian Katsch
- Institut
für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Qiuyang Li
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xiaoyang Zhu
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Andreas Knorr
- Institut
für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Giulio Cerullo
- Dipartimento
di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
| | - Stefano Dal Conte
- Dipartimento
di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, I-20133 Milano, Italy
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5
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Katsch F, Selig M, Knorr A. Exciton-Scattering-Induced Dephasing in Two-Dimensional Semiconductors. PHYSICAL REVIEW LETTERS 2020; 124:257402. [PMID: 32639791 DOI: 10.1103/physrevlett.124.257402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/25/2020] [Accepted: 06/01/2020] [Indexed: 05/13/2023]
Abstract
Enhanced Coulomb interactions in monolayer transition metal dichalcogenides cause tightly bound electron-hole pairs (excitons) that dominate their linear and nonlinear optical response. The latter includes bleaching, energy renormalizations, and higher-order Coulomb correlation effects like biexcitons and excitation-induced dephasing. While the first three are extensively studied, no theoretical footing for excitation-induced dephasing in exciton-dominated semiconductors is available so far. In this Letter, we present microscopic calculations based on excitonic Heisenberg equations of motion and identify the coupling of optically pumped excitons to exciton-exciton scattering continua as the leading mechanism responsible for an optical-power-dependent linewidth broadening (excitation-induced dephasing) and sideband formation. Performing time-, momentum-, and energy-resolved simulations, we quantitatively evaluate the exciton-induced dephasing for the most common monolayer transition metal dichalcogenides and find an excellent agreement with recent experiments.
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Affiliation(s)
- Florian Katsch
- Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Malte Selig
- Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, 10623 Berlin, Germany
| | - Andreas Knorr
- Institut für Theoretische Physik, Nichtlineare Optik und Quantenelektronik, Technische Universität Berlin, 10623 Berlin, Germany
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6
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Brem S, Lin KQ, Gillen R, Bauer JM, Maultzsch J, Lupton JM, Malic E. Hybridized intervalley moiré excitons and flat bands in twisted WSe 2 bilayers. NANOSCALE 2020; 12:11088-11094. [PMID: 32400821 DOI: 10.1039/d0nr02160a] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The large surface-to-volume ratio in atomically thin 2D materials allows to efficiently tune their properties through modifications of their environment. Artificial stacking of two monolayers into a bilayer leads to an overlap of layer-localized wave functions giving rise to a twist angle-dependent hybridization of excitonic states. In this joint theory-experiment study, we demonstrate the impact of interlayer hybridization on bright and momentum-dark excitons in twisted WSe2 bilayers. In particular, we show that the strong hybridization of electrons at the Λ point leads to a drastic redshift of the momentum-dark K-Λ exciton, accompanied by the emergence of flat moiré exciton bands at small twist angles. We directly compare theoretically predicted and experimentally measured optical spectra allowing us to identify photoluminescence signals stemming from phonon-assisted recombination of layer-hybridized dark excitons. Moreover, we predict the emergence of additional spectral features resulting from the moiré potential of the twisted bilayer lattice.
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Affiliation(s)
- Samuel Brem
- Chalmers University of Technology, Department of Physics, Gothenburg, Sweden.
| | - Kai-Qiang Lin
- University of Regensburg, Institute of Experimental and Applied Physics, Regensburg, Germany.
| | - Roland Gillen
- Friedrich-Alexander University Erlangen-Nuernberg, Institute of Condensed Matter Physics, Germany
| | - Jonas M Bauer
- University of Regensburg, Institute of Experimental and Applied Physics, Regensburg, Germany.
| | - Janina Maultzsch
- Friedrich-Alexander University Erlangen-Nuernberg, Institute of Condensed Matter Physics, Germany
| | - John M Lupton
- University of Regensburg, Institute of Experimental and Applied Physics, Regensburg, Germany.
| | - Ermin Malic
- Chalmers University of Technology, Department of Physics, Gothenburg, Sweden.
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7
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Brem S, Ekman A, Christiansen D, Katsch F, Selig M, Robert C, Marie X, Urbaszek B, Knorr A, Malic E. Phonon-Assisted Photoluminescence from Indirect Excitons in Monolayers of Transition-Metal Dichalcogenides. NANO LETTERS 2020; 20:2849-2856. [PMID: 32084315 PMCID: PMC7307964 DOI: 10.1021/acs.nanolett.0c00633] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Indexed: 05/23/2023]
Abstract
The photoluminescence (PL) spectrum of transition-metal dichalcogenides (TMDs) shows a multitude of emission peaks below the bright exciton line, and not all of them have been explained yet. Here, we study the emission traces of phonon-assisted recombinations of indirect excitons. To this end, we develop a microscopic theory describing simultaneous exciton, phonon, and photon interaction and including consistent many-particle dephasing. We explain the drastically different PL below the bright exciton in tungsten- and molybdenum-based materials as the result of different configurations of bright and momentum-dark states. In good agreement with experiments, our calculations predict that WSe2 exhibits clearly visible low-temperature PL signals stemming from the phonon-assisted recombination of momentum-dark K-K' excitons.
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Affiliation(s)
- Samuel Brem
- Department
of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - August Ekman
- Department
of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Dominik Christiansen
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Florian Katsch
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Malte Selig
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Cedric Robert
- Laboratoire
de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse, INSA-CNRS-UPS, 31077 Toulouse, France
| | - Xavier Marie
- Laboratoire
de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse, INSA-CNRS-UPS, 31077 Toulouse, France
| | - Bernhard Urbaszek
- Laboratoire
de Physique et Chimie des Nano-objets (LPCNO), Université de Toulouse, INSA-CNRS-UPS, 31077 Toulouse, France
| | - Andreas Knorr
- Institute
of Theoretical Physics, Technical University
Berlin, 10623 Berlin, Germany
| | - Ermin Malic
- Department
of Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden
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8
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Beloussov IV, Khadzhi PI, Corovai AV, Markov DA. Nonlinear transmission and reflection of ultrashort laser pulses by a thin semiconductor film under two-photon generation of biexcitons. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:225802. [PMID: 21572228 DOI: 10.1088/0953-8984/23/22/225802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The transmission and reflection of an ultrashort laser pulse by a thin semiconductor film under the conditions of resonance excitation of biexcitons by two photons are theoretically investigated. The numerical solutions of the macroscopic equations are found for various values of the film thickness, the detuning from the two-photon resonance, the laser pulse duration, and the intensity. These equations have been obtained in the framework of the generalized bipolariton model. In this model a biexciton is formed from virtual excitons of four kinds and only some of them interact with the light. It is shown that the thin film substantially transforms the incident pulse. For specific conditions, high and narrow transmission and reflection peaks can appear, or even trains of such peaks. In some cases their height can considerably exceed the amplitude of the incident pulse. The results are compared with similar results obtained on the basis of other models.
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Affiliation(s)
- Igor V Beloussov
- Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev, Republic of Moldova.
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9
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Laikhtman B. Are excitons really bosons? JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:295214. [PMID: 21483066 DOI: 10.1088/0953-8984/19/29/295214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Non-bosonic commutation relations of exciton operators discovered by Keldysh and Kozlov (1968 Zh. Eksp. Teor. Fiz. 54 978; 1968 Sov. Phys.-JETP 27 521 (Engl. Transl.)) led to a long-standing question about the possible difference between excitons and bosons in spite of the integer spin of excitons. In this paper the problem is analysed and it is shown that, in spite of the difference between separate excitons and bosons, the exciton gas is a Bose gas. Bosons comprising this gas are mixtures of separate excitons, and the non-bosonic nature of excitons leads only to a renormalization of the interaction between them. Features of the exciton luminescence coming from the interaction and non-bosonic nature of excitons are considered.
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Affiliation(s)
- B Laikhtman
- Racah Institute of Physics, Hebrew University, Jerusalem 91904, Israel
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10
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Jankowska-Frydel A, Kukliński B, Nowosielski T, Grinberg M. The influence of the heat treatment on luminescence and EPR spectra of mixed NaxK1−xCl single crystals. RADIAT MEAS 2001. [DOI: 10.1016/s1350-4487(01)00105-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Axt VM, Haase B, Neukirch U. Influence of two-pair continuum correlations following resonant excitation of excitons. PHYSICAL REVIEW LETTERS 2001; 86:4620-4623. [PMID: 11384298 DOI: 10.1103/physrevlett.86.4620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2000] [Indexed: 05/23/2023]
Abstract
The memory structure induced by coherent transitions to the exciton-exciton scattering continuum is shown to have significant influence on spectrally resolved four-wave-mixing signals even under selective excitation of 1s excitons. Comparisons between experiments and calculations that account nonperturbatively for these quantum kinetic Coulomb correlations demonstrate large compensations between mean-field contributions and transitions to the two-pair continuum. Experiments with different polarizations of the laser pulses show that two-pair continuum correlations are responsible for delay-time dependent shifts of the excitonic emission as well as for substantial deformations of the line shape.
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Affiliation(s)
- V M Axt
- Institut für Festkörpertheorie, Westfälische Wilhelms Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster, Germany
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12
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13
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Gallagher FB, Spano FC. Theory of biexcitons in one-dimensional polymers. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:3790-3803. [PMID: 9983929 DOI: 10.1103/physrevb.53.3790] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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14
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15
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Ivanov AL, Hasuo M, Nagasawa N, Haug H. Two-photon generation of excitonic molecules in CuCl: An exactly solvable bipolariton model and high-precision experiments. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:11017-11033. [PMID: 9980200 DOI: 10.1103/physrevb.52.11017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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16
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Ivanov AL, Haug H. Radiative renormalizations for excitonic molecules. PHYSICAL REVIEW LETTERS 1995; 74:438-441. [PMID: 10058758 DOI: 10.1103/physrevlett.74.438] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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17
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Shimano R, Kuwata-Gonokami M. Observation of Autler-Townes splitting of biexcitons in CuCl. PHYSICAL REVIEW LETTERS 1994; 72:530-533. [PMID: 10056456 DOI: 10.1103/physrevlett.72.530] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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18
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Bigot J, Daunois A, Oberlé J, Merle J. Femtosecond dephasing in CdSxSe1-x mixed crystals: The role of localized biexcitons. PHYSICAL REVIEW LETTERS 1993; 71:1820-1823. [PMID: 10054508 DOI: 10.1103/physrevlett.71.1820] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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