AI Chat Paper
Note: Please note that the following content is generated by AMiner AI. SciOpen does not take any responsibility related to this content.
{{lang === 'zh_CN' ? '文章概述' : 'Summary'}}
{{lang === 'en_US' ? '中' : 'Eng'}}
Chat more with AI
Powered by AMiner. Clicking this button will take you away from SciOpen.
Home Nano Research Article
Article Link
Cite
EndNote(RIS) BibTeX
Collect
Submit Manuscript
Show Outline
Outline
Show full outline
Hide outline
Outline
Show full outline
Hide outline
Research Article

Large valley-polarized state in single-layer NbX2 (X = S, Se): Theoretical prediction

Yanmei Zang, Yandong Ma( ), Rui Peng, Hao Wang, Baibiao Huang, Ying Dai( )
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Shandanan Street 27, Jinan 250100, China
Show Author Information

Graphical Abstract

Abstract

Exploring two-dimensional valleytronic crystals with large valley-polarized state is of considerable importance due to the promising applications in next-generation information related devices. Here, we show first-principles evidence that single-layer NbX2 (X = S, Se) is potentially the long-sought two-dimensional valleytronic crystal. Specifically, the valley-polarized state is found to occur spontaneously in single-layer NbX2, without needing any external tuning, which arises from their intrinsic magnetic exchange interaction and inversion asymmetry. Moreover, the strong spin-orbit coupling strength within Nb-d orbitals renders their valley- polarized states being of remarkably large (NbS2 ~ 156 meV/NbSe2 ~ 219 meV), enabling practical utilization of their valley physics accessible. In additional, it is predicted that the valley physics (i.e., anomalous valley Hall effect) in single-layer NbX2 is switchable via applying moderate strain. These findings make single-layer NbX2 tantalizing candidates for realizing high-performance and controllable valleytronic devices.

Keywords

valley polarizationferromagneticanomalous valley Hall effectNbX2 (X = S, Se)first-principles

Electronic Supplementary Material

Download File(s)
12274_2020_3121_MOESM1_ESM.pdf (3.1 MB)

References

[1]
D. Xiao,; W. Yao,; Q. Niu, Valley-contrasting physics in graphene: Magnetic moment and topological transport. Phys. Rev. Lett. 2007, 99, 236809.
Crossref Google Scholar
[2]
W. Yao,; D. Xiao,; Q. Niu, Valley-dependent optoelectronics from inversion symmetry breaking. Phys. Rev. B 2008, 77, 235406.
Crossref Google Scholar
[3]
F. Zhang,; J. Jung,; G. A. Fiete,; Q. Niu,; A. H. MacDonald, Spontaneous quantum Hall states in chirally stacked few-layer graphene systems. Phys. Rev. Lett. 2011, 106, 156801.
Crossref Google Scholar
[4]
Y. D. Ma,; L. Z. Kou,; A. J. Du,; B. B. Huang,; Y. Dai,; T. Heine, Conduction-band valley spin splitting in single-layer H-Tl2O. Phys. Rev. B 2018, 97, 035444.
Google Scholar
[5]
D. Xiao,; G. B. Liu,; W. X. Feng,; X. D. Xu,; W. Yao, Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 2012, 108, 196802.
Crossref Google Scholar
[6]
C. A. Lei,; Y. D. Ma,; T. Zhang,; X. L. Xu,; B. B. Huang,; Y. Dai, Valley polarization in monolayer CrX2 (X = S, Se) with magnetically doping and proximity coupling. New J. Phys. 2020, 22, 033002.
Crossref Google Scholar
[7]
J. R. Schaibley,; H. Y. Yu,; G. Clark,; P. Rivera,; J. S. Ross,; K. L. Seyler,; W. Yao,; X. D. Xu, Valleytronics in 2D materials. Nat. Rev. Mater. 2016, 1, 16055.
Crossref Google Scholar
[8]
Q. Pei,; B. Z. Zhou,; W. B. Mi,; C. Y. Cheng, Triferroic material and electrical control of valley degree of freedom. ACS Appl. Mater. Interfaces 2019, 11, 12675-12682
Crossref Google Scholar
[9]
H. L. Zeng,; J. F. Dai,; W. Yao,; D. Xiao,; X. D. Cui, Valley polarization in MoS2 monolayers by optical pumping. Nat. Nanotechnol. 2012, 7, 490-493.
Crossref Google Scholar
[10]
T. Cao,; G. Wang,; W. P. Han,; H. Q. Ye,; C. R. Zhu,; J. R. Shi,; Q. Niu,; P. H. Tan,; E. G. Wang,; B. L.; Liu, et al. Valley-selective circular dichroism of monolayer molybdenum disulphide. Nat. Commun. 2012, 3, 887.
Crossref Google Scholar
[11]
P. Zhao,; Y. D. Ma,; C. A. Lei,; H. Wang,; B. B. Huang,; Y. Dai, Single-layer LaBr2: Two-dimensional valleytronic semiconductor with spontaneous spin and valley polarizations. Appl. Phys. Lett. 2019, 115, 261605.
Crossref Google Scholar
[12]
K. F. Mak,; K. L. He,; J. Shan,; T. F. Heinz, Control of valley polarization in monolayer MoS2 by optical helicity. Nat. Nanotechnol. 2012, 7, 494-498.
Crossref Google Scholar
[13]
N. Singh,; U. Schwingenschlogl, A route to permanent valley polarization in monolayer MoS2. Adv. Mater. 2017, 29, 1600970.
Crossref Google Scholar
[14]
X. L. Xu,; Y. D. Ma,; T. Zhang,; C. A. Lei,; B. B. Huang,; Y. Dai, Nonmetal-atom-doping-induced valley polarization in single-layer Tl2O. J. Phys. Chem. Lett. 2019, 10, 4535-4541.
Crossref Google Scholar
[15]
Q. Y. Zhang,; S. A. Yang,; W. B. Mi,; Y. C. Cheng,; U. Schwingenschlögl, Large spin-valley polarization in monolayer MoTe2 on top of EuO(111). Adv. Mater. 2016, 28, 959-966.
Crossref Google Scholar
[16]
N. B. Li,; J. Y. Zhang,; Y. Xue,; T. Zhou,; Z. Q. Yang, Large valley polarization in monolayer MoTe2 on a magnetic substrate. Phys. Chem. Chem. Phys. 2018, 20, 3805-3812.
Crossref Google Scholar
[17]
J. S. Qi,; X. Li,; Q. Niu,; J. Feng, Giant and tunable valley degeneracy splitting in MoTe2. Phys. Rev. B 2015, 92, 121403.
Google Scholar
[18]
X. F. Ma,; L. Yin,; J. J. Zou,; W. B. Mi,; X. C. Wang, Strain-tailored valley polarization and magnetic anisotropy in two-dimensional 2H-VS2/Cr2C heterostructures. J. Phys. Chem. C 2019, 123, 17440-17448.
Crossref Google Scholar
[19]
R. Peng,; Y. D. Ma,; S. Zhang,; B. B. Huang,; Y. Dai, Valley polarization in Janus single-layer MoSSe via magnetic doping. J. Phys. Chem. Lett. 2018, 9, 3612-3617.
Crossref Google Scholar
[20]
T. C. Berkelbach,; M. S. Hybertsen,; D. R. Reichman, Theory of neutral and charged excitons in monolayer transition metal dichalcogenides. Phys. Rev. B 2013, 88, 045318.
Crossref Google Scholar
[21]
H. Z. Lu,; W. Yao,; D. Xiao,; S. Q. Shen, Intervalley scattering and localization behaviors of spin-valley coupled Dirac fermions. Phys. Rev. Lett. 2013, 110, 016806.
Crossref Google Scholar
[22]
O. L. Sanchez,; D. Ovchinnikov,; S. Misra,; A. Allain,; A. Kis, Valley polarization by spin injection in a light-emitting van der Waals heterojunction. Nano Lett. 2016, 16, 5792-5797.
Crossref Google Scholar
[23]
C. M. Zhang,; Y. H. Nie,; S. Sanvito,; A. J. Du, First-principles prediction of a room-temperature ferromagnetic Janus VSSe monolayer with piezoelectricity, ferroelasticity, and large valley polarization. Nano Lett. 2019, 19, 1366-1370.
Crossref Google Scholar
[24]
L. Z. Kou,; S. C. Wu,; C. Felser,; T. Frauenheim,; C. F. Chen,; B. H. Yan, Robust 2D topological insulators in van der Waals heterostructures. ACS Nano 2014, 8, 10448-10454.
Crossref Google Scholar
[25]
L. Z. Kou,; B. H. Yan,; F. M. Hu,; S. C. Wu,; T. O. Wehling,; C. Felser,; C. F. Chen,; T. Frauenheim, Graphene-based topological insulator with an intrinsic bulk band gap above room temperature. Nano Lett. 2013, 13, 6251-6255.
Crossref Google Scholar
[26]
L. Z. Kou,; F. M. Hu,; B. H. Yan,; T. Wehling,; C. Felser,; T. Frauenheim,; C. F. Chen, Proximity enhanced quantum spin Hall state in graphene. Carbon 2015, 87, 418-423.
Crossref Google Scholar
[27]
D. MacNeill,; C. Heikes,; K. F. Mak,; Z. Anderson,; A. Kormányos,; V. Zólyomi,; J. Park,; D. C. Ralph, Breaking of valley degeneracy by magnetic field in monolayer MoSe2. Phys. Rev. Lett. 2015, 114, 037401.
Crossref Google Scholar
[28]
Y. L. Li,; J. Ludwig,; T. Low,; A. Chernikov,; X. Cui,; G. Arefe,; Y. D. Kim,; A. M. Van Der Zande,; A. Rigosi,; H. M. Hill, et al. Valley splitting and polarization by the Zeeman effect in monolayer MoSe2. Phys. Rev. Lett. 2014, 113, 266804.
Crossref Google Scholar
[29]
Y. J. Wu,; C. Shen,; Q. H. Tan,; J. Shi,; X. F. Liu,; Z. H. Wu,; J. Zhang,; P. H. Tan,; H. Z. Zheng, Valley Zeeman splitting of monolayer MoS2 probed by low-field magnetic circular dichroism spectroscopy at room temperature. Appl. Phys. Lett. 2018, 112, 153105.
Crossref Google Scholar
[30]
B. Huang,; G. Clark,; E. Navarro-Moratalla,; D. R. Klein,; R. Cheng,; K. L. Seyler,; D. Zhong,; E. Schmidgall,; M. A. Mcguire,; D. H. Cobden, et al. Layer-dependent ferromagnetism in a van der Waals crystal down to the monolayer limit. Nature 2017, 546, 270-273.
Crossref Google Scholar
[31]
C. Gong,; L. Li,; Z. L. Li,; H. W. Ji,; A. Stern,; Y. Xia,; T. Cao,; W. Bao,; C. Z. Wang,; Y. Wang, et al. Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals. Nature 2017, 546, 265-269.
Crossref Google Scholar
[32]
C. X. Huang,; J. S. Feng,; F. Wu,; D. Ahmed,; B. Huang,; H. J. Xiang,; K. M. Deng,; E. Kan, Toward intrinsic room-temperature ferromagnetism in two-dimensional semiconductors. J. Am. Chem. Soc. 2018, 140, 11519-11525.
Crossref Google Scholar
[33]
N. H. Miao,; B. Xu,; L. G. Zhu,; J. Zhou,; Z. M. Sun, 2D intrinsic ferromagnets from van der Waals antiferromagnets. J. Am. Chem. Soc. 2018, 140, 2417-2420.
Crossref Google Scholar
[34]
C. X. Huang,; Y. P. Du,; H. P. Wu,; H. J. Xiang,; K. M. Deng,; E. Kan, Prediction of intrinsic ferromagnetic ferroelectricity in a transition-metal halide monolayer. Phys. Rev. Lett. 2018, 120, 147601.
Crossref Google Scholar
[35]
P. H. Jiang,; C. Wang,; D. C. Chen,; Z. C. Zhong,; Z. Yuan,; Z. Y. Lu,; W. Ji, Stacking tunable interlayer magnetism in bilayer CrI3. Phys. Rev. B 2019, 99, 144401.
Crossref Google Scholar
[36]
W. Y. Tong,; S. J. Gong,; X. G. Wan,; C. G. Duan, Concepts of ferrovalley material and anomalous valley Hall effect. Nat. Commun. 2016, 7, 13612.
Crossref Google Scholar
[37]
P. Zhao,; Y. D. Ma,; H. Wang,; B. B. Huang,; L. Z. Kou,; Y. Dai, Intrinsic valley polarization and anomalous valley Hall effect in single-layer 2H-FeCl2. arXiv: 2003.04561, 2020.
[38]
R. Peng,; Y. D. Ma,; X. L. Xu,; Z. L. He,; B. B. Huang,; Y. Dai, Intrinsic anomalous valley Hall effect in single-layer Nb3I8. Phys. Rev. B 2020, 102, 035412.
Crossref Google Scholar
[39]
W. W. Zhao,; B. H. Dong,; Z. L. Guo,; G. Su,; R. J. Gao,; W. Wang,; L. X. Cao, Colloidal synthesis of VSe2 single-layer nanosheets as novel electrocatalysts for the hydrogen evolution reaction. Chem. Commun. 2016, 52, 9228-9231.
Crossref Google Scholar
[40]
K. Krämer,; T. Schleid,; M. Schulze,; W. Urland,; G. Meyer, Three bromides of lanthanum: LaBr2, La2Br5, and LaBr3. Z. Anorg. Allg. Chem. 1989, 575, 61-70.
Crossref Google Scholar
[41]
N. J. Doran,; D. J. Titterington,; B. Ricco,; G. Wexler, A tight binding fit to the bandstructure of 2H-NbSe2 and NbS2. J. Phys. C: Solid State Phys. 1978, 11, 685.
Crossref Google Scholar
[42]
H. Wang,; X. W. Huang,; J. H. Lin,; J. Cui,; Y. Chen,; C. Zhu,; F. C. Liu,; Q. S. Zeng,; J. D. Zhou,; P. Yu, et al. High-quality monolayer superconductor NbSe2 grown by chemical vapour deposition. Nat. Commun. 2017, 8, 394.
Crossref Google Scholar
[43]
X. J. Zhu,; Y. Q. Guo,; H. Cheng,; J. Dai,; X. D. An,; J. Y. Zhao,; K. Z. Tian,; S. Q. Wei,; X. C. Zeng,; C. Z. Wu, et al. Signature of coexistence of superconductivity and ferromagnetism in two- dimensional NbSe2 triggered by surface molecular adsorption. Nat. Commun. 2016, 7, 11210.
Crossref Google Scholar
[44]
C. S. Lian,; C. Si,; W. H. Duan, Unveiling charge-density wave, superconductivity, and their competitive nature in two-dimensional NbSe2 Nano Lett. 2018, 18, 2924-2929.
Crossref Google Scholar
[45]
R. Yan,; G. Khalsa,; B. T. Schaefer,; A. Jarjour,; S. Rouvimov,; K. C. Nowack,; H. G. Xing,; D. Jena, Thickness dependence of superconductivity in ultrathin NbS2 Appl. Phys. Express 2019, 12, 023008.
Crossref Google Scholar
[46]
S. H. Zhao,; T. Hotta,; T. Koretsune,; K. Watanabe,; T. Taniguchi,; K. Sugawara, T. Takahashi,; H. Shinohara,; R. Kitaura, Two-dimensional metallic NbS2: Growth, optical identification and transport properties. 2D Mater. 2016, 3, 025027.
Crossref Google Scholar
[47]
Y. D. Ma,; A. Kuc,; Y. Jing,; P. Philipsen,; T. Heine, Two-dimensional haeckelite NbS2: A diamagnetic high-mobility semiconductor with Nb4+ ions. Angew. Chem., Int. Ed. 2017, 56, 10214-10218.
Crossref Google Scholar
[48]
Y. Xu,; X. F. Liu,; W. L. Guo, Tensile strain induced switching of magnetic states in NbSe2 and NbS2 single layers. Nanoscale 2014, 6, 12929-12933.
Crossref Google Scholar
[49]
Y. J. Sun,; Z. W. Zhuo,; X. J. Wu, Bipolar magnetism in a two-dimensional NbS2 semiconductor with high curie temperature. J. Mater. Chem. C 2018, 6, 11401-11406.
Crossref Google Scholar
[50]
Y. G. Zhou,; Z. G. Wang,; P. Yang,; X. T. Zu,; L. Yang,; X. Sun,; F. Gao, Tensile strain switched ferromagnetism in layered NbS2 and NbSe2 ACS Nano 2012, 6, 9727-9736.
Crossref Google Scholar
[51]
Y. Wang,; M. Qiao,; Y. F. Li,; Z. F. Chen, A two-dimensional CaSi monolayer with quasi-planar pentacoordinate silicon. Nanoscale Horiz. 2018, 3, 327-334.
Crossref Google Scholar
[52]
R. Peng,; Y. D. Ma,; B. B. Huang,; Y. Dai, Two-dimensional Janus PtSSe for photocatalytic water splitting under the visible or infrared light. J. Mater. Chem. A 2019, 7, 603-610.
Crossref Google Scholar
[53]
Y. Ding,; Y. L. Wang, Density functional theory study of the silicene-like SiX and XSi3 (X = B, C, N, Al, P) honeycomb lattices: The various buckled structures and versatile electronic properties. J. Phys. Chem. C 2013, 117, 18266-18278.
Crossref Google Scholar
[54]
E. Cadelano,; P. L. Palla,; S. Giordano,; L. Colombo, Elastic properties of hydrogenated graphene. Phys. Rev. B 2010, 82, 235414.
Crossref Google Scholar
[55]
R. Peng,; Y. D. Ma,; Z. L. He,; B. B. Huang,; L. Z. Kou,; Y. Dai, Single-layer Ag2S: A two-dimensional bidirectional auxetic semiconductor. Nano Lett. 2019, 19, 1227-1233.
Crossref Google Scholar
[56]
R. C. Andrew,; R. E. Mapasha,; A. M. Ukpong,; N. Chetty, Mechanical properties of graphene and boronitrene. Phys. Rev. B 2012, 85, 125428.
Crossref Google Scholar
[57]
K. H. Michel,; B. Verberck, Theory of elastic and piezoelectric effects in two-dimensional hexagonal boron nitride. Phys. Rev. B 2009, 80, 224301.
Crossref Google Scholar
[58]
Z. B. Gao,; X. Dong,; N. B. Li,; J. Ren, Novel two-dimensional silicon dioxide with in-plane negative Poisson’s ratio. Nano Lett. 2017, 17, 772-777.
Crossref Google Scholar
[59]
C. Gong,; H. J. Zhang,; W. H. Wang,; L. Colombo,; R. M. Wallace,; K. Cho, Band alignment of two-dimensional transition metal dichalcogenides: Application in tunnel field effect transistors. Appl. Phys. Lett. 2013, 103, 053513.
Crossref Google Scholar
[60]
D. J. Thouless,; M. Kohmoto,; M. P. Nightingale,; M. den Nijs, Quantized Hall conductance in a two-dimensional periodic potential. Phys. Rev. Lett. 1982, 49, 405-408.
Crossref Google Scholar
[61]
G. Kresse,; J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 1996, 54, 11169-11186.
Crossref Google Scholar
[62]
G. Kresse,; J. Furthmüller, Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 1996, 6, 15-50.
Crossref Google Scholar
[63]
H. J Monkhorst,; J. D. Pack, Special points for Brillouin-zone integrations. Phys. Rev. B 1976, 13, 5188-5192.
Crossref Google Scholar
[64]
J. P. Perdew,; K. Burke,; M. Ernzerhof, Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865.
Crossref Google Scholar
[65]
G. Kresse,; D. Joubert, From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999, 59, 1758-1775.
Crossref Google Scholar
[66]
J. Heyd,; G. E. Scuseria,; M. Ernzerhof, Hybrid functionals based on a screened Coulomb potential. J. Chem. Phys. 2003, 118, 8207-8215.
Crossref Google Scholar
[67]
A. Togo,; F. Oba,; I. Tanaka, First-principles calculations of the ferroelastic transition between rutile-type and CaCl2-type SiO2 at high pressures. Phys. Rev. B 2008, 78, 134106.
Crossref Google Scholar
[68]
A. A. Mostofi,; J. R. Yates,; Y. S. Lee,; I. Souza,; D. Vanderbilt,; N. Marzari, wannier90: A tool for obtaining maximally-localised Wannier functions. Comput. Phys. Commun. 2008, 178, 685-699.
Crossref Google Scholar
Nano Research
Volume 14 Issue 3,
March 2021
Pages 834-839
DOI: 10.1007/s12274-020-3121-1
Cite this article:
Zang Y, Ma Y, Peng R, et al. Large valley-polarized state in single-layer NbX2 (X = S, Se): Theoretical prediction. Nano Research, 2021, 14(3): 834-839. https://doi.org/10.1007/s12274-020-3121-1
Topics:
CrystalsNiobium compoundsSelenium compoundsSpin orbit couplingVanadium compounds

997

Views

69

Crossref

0

Web of Science

67

Scopus

0

CSCD

Altmetrics
Received: 16 July 2020
Revised: 24 August 2020
Accepted: 15 September 2020
Published: 01 March 2021
© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature 2020
Return