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Xu Y, Wang Y, Yu S, Sun D, Dai Y, Huang B, Wei W. High-Temperature Excitonic Condensation in 2D Lattice. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2404436. [PMID: 39239846 DOI: 10.1002/advs.202404436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 07/24/2024] [Indexed: 09/07/2024]
Abstract
Exploration of high-temperature bosonic condensation is of significant importance for the fundamental many-body physics and applications in nanodevices, which, however, remains a huge challenge. Here, in combination of many-body perturbation theory and first-principles calculations, a new-type spatially indirect exciton can be optically generated in two-dimensional (2D) Bi2S2Te because of its unique structure feature. In particular, the spin-singlet spatially indirect excitons in Bi2S2Te monolayer are dipole/parity allowed and reveal befitting characteristics for excitonic condensation, such as small effective mass and satisfied dilute limitation. Based on the layered Bi2S2Te, the possibility of the high-temperature excitonic Bose-Einstein condensation (BEC) and superfluid state in two dimensions, which goes beyond the current paradigms in both experiment and theory, are proved. It should be highlighted that record-high phase transition temperatures of 289.7 and 72.4 K can be theoretically predicted for the excitonic BEC and superfluidity in the atomic thin Bi2S2Te, respectively. It therefore can be confirmed that Bi2S2Te featuring bound bosonic states is a fascinating 2D platform for exploring the high-temperature excitonic condensation and applications in such as quantum computing and dissipationless nanodevices.
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Affiliation(s)
- Yushuo Xu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Yuanyuan Wang
- Science, Mathematics and Technology Cluster, Singapore University of Technology and Design, Singapore, 487372, Singapore
| | - Shiqiang Yu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Dongyue Sun
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Wei Wei
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
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Qiu ZY, Tao YL, Liu QJ, Liu ZT. First-principles study of the structure, electronic and optical properties of monolayer ZrX 3 (X = S, Se, Te). J Mol Model 2024; 30:317. [PMID: 39207575 DOI: 10.1007/s00894-024-06112-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Accepted: 08/15/2024] [Indexed: 09/04/2024]
Abstract
CONTEXT AND RESULTS The structure, electronic and optical properties of single-layer transition metallic chalcogenides ZrX3 (X = S, Se, Te) have been studied by density functional theory. The electron energy dispersion curve shows that ZrX3 has semiconductor properties, in which the conduction band is mainly contributed by the correlated states of the Zr-d orbital, and the valence band is mainly contributed by the correlated states of the X-p orbital. It is found that b-axis and biaxial strain have great influence on the bandgap and the shift of density of states is also large. At the same time, the peak value of density of states increases greatly when biaxial strain is applied. It is of guiding significance for selecting suitable substrates to prepare two-dimensional ZrX3 materials to study their electronic properties. The calculation of optical constants confirms that ZrX3 has strong optical anisotropy. In the visible range, the light absorption efficiency of ZrX3 in the direction of electric field polarization [100] is higher than that in the direction of [010]. The reflectance spectral results show that ZrS3 and ZrSe3 in the [100] directions have the highest reflectance, and ZrTe3 in the [010] direction has the highest reflectance, even in the long electromagnetic radiation range (up to 10 eV), which is of great significance for the construction of visible optical devices. COMPUTATIONAL METHOD All computations have been carried out based on density functional theory (DFT) as implemented in the CASTEP code. The pseudo-potential is adopted by the norm conserving, and the exchange correlation functional is adopted by the Perdew-Burke-Ernzerhof in local generalized gradient approximation (GGA).
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Affiliation(s)
- Zhi-Yuan Qiu
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Ya-Le Tao
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.
| | - Qi-Jun Liu
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Zheng-Tang Liu
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
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Baghdasaryan DA, Harutyunyan VA, Kazaryan EM, Sarkisyan HA, Petrosyan LS, Shahbazyan TV. Possibility of Exciton Bose-Einstein Condensation in CdSe Nanoplatelets. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2734. [PMID: 37836375 PMCID: PMC10574473 DOI: 10.3390/nano13192734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/01/2023] [Accepted: 10/06/2023] [Indexed: 10/15/2023]
Abstract
The quasi-two-dimensional exciton subsystem in CdSe nanoplatelets is considered. It is theoretically shown that Bose-Einstein condensation (BEC) of excitons is possible at a nonzero temperature in the approximation of an ideal Bose gas and in the presence of an "energy gap" between the ground and the first excited states of the two-dimensional exciton center of inertia of the translational motion. The condensation temperature (Tc) increases with the width of the "gap" between the ground and the first excited levels of size quantization. It is shown that when the screening effect of free electrons and holes on bound excitons is considered, the BEC temperature of the exciton subsystem increases as compared to the case where this effect is absent. The energy spectrum of the exciton condensate in a CdSe nanoplate is calculated within the framework of the weakly nonideal Bose gas approximation, considering the specifics of two-dimensional Born scattering.
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Affiliation(s)
- Davit A. Baghdasaryan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
| | - Volodya A. Harutyunyan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
| | - Eduard M. Kazaryan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
| | - Hayk A. Sarkisyan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
- Institute of Electronics and Telecommunications, Peter the Great Saint-Petersburg Polytechnical University, 195251 Saint-Petersburg, Russia
| | - Lyudvig S. Petrosyan
- Department of Physics, Jackson State University, Jackson, MS 39217, USA; (L.S.P.); (T.V.S.)
| | - Tigran V. Shahbazyan
- Department of Physics, Jackson State University, Jackson, MS 39217, USA; (L.S.P.); (T.V.S.)
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Chen M, Li L, Xu M, Li W, Zheng L, Wang X. Quasi-One-Dimensional van der Waals Transition Metal Trichalcogenides. RESEARCH (WASHINGTON, D.C.) 2023; 6:0066. [PMID: 36930809 PMCID: PMC10013805 DOI: 10.34133/research.0066] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/12/2023] [Indexed: 01/21/2023]
Abstract
The transition metal trichalcogenides (TMTCs) are quasi-one-dimensional (1D) MX3-type van der Waals layered semiconductors, where M is a transition metal element of groups IV and V, and X indicates chalcogen element. Due to the unique quasi-1D crystalline structures, they possess several novel electrical properties such as variable bandgaps, charge density waves, and superconductivity, and highly anisotropic optical, thermoelectric, and magnetic properties. The study of TMTCs plays an essential role in the 1D quantum materials field, enabling new opportunities in the material research dimension. Currently, tremendous progress in both materials and solid-state devices has been made, demonstrating promising applications in the realization of nanoelectronic devices. This review provides a comprehensive overview to survey the state of the art in materials, devices, and applications based on TMTCs. Firstly, the symbolic structure, current primary synthesis methods, and physical properties of TMTCs have been discussed. Secondly, examples of TMTC applications in various fields are presented, such as photodetectors, energy storage devices, catalysts, and sensors. Finally, we give an overview of the opportunities and future perspectives for the research of TMTCs, as well as the challenges in both basic research and practical applications.
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Affiliation(s)
- Mengdi Chen
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an710072, China
| | - Lei Li
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an710072, China
| | - Manzhang Xu
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an710072, China
| | - Weiwei Li
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an710072, China
| | - Lu Zheng
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an710072, China
| | - Xuewen Wang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,Shaanxi Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.,MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an710072, China.,Key Laboratory of Flexible Electronics of Zhejiang Provience, Ningbo Institute of Northwestern Polytechnical University, 218 Qingyi Road, Ningbo 315103, China
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Guo H, Zhang X, Lu G. Tuning moiré excitons in Janus heterobilayers for high-temperature Bose-Einstein condensation. SCIENCE ADVANCES 2022; 8:eabp9757. [PMID: 36206334 PMCID: PMC9544320 DOI: 10.1126/sciadv.abp9757] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
Abstract
Using first-principles calculations, we predict that moiré excitons in twisted Janus heterobilayers could realize tunable and high-temperature Bose-Einstein condensation (BEC). The electric dipole in the Janus heterobilayers leads to charge-transfer interlayer and intralayer moiré excitons with exceptionally long lifetimes, in the absence of spacer layers. The electric dipole is also expected to enhance exciton-exciton repulsions at high exciton densities and can modulate moiré potentials that trap excitons for their condensation. The key parameters for exciton condensation, including exciton Bohr radius, binding energy, effective mass, and critical Mott density, are examined as a function of the twist angle. Last, exciton phase diagrams for the Janus heterobilayers are constructed from which one can estimate the BEC (>100 K) and superfluid (~30 K) transition temperatures. In addition to indirect interlayer excitons, we find that direct intralayer excitons can also condense at high temperatures, consistent with experiments.
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