AI Chat Paper
Discover the SciOpen Platform and Achieve Your Research Goals with Ease.
Search articles, authors, keywords, DOl and etc.
{{expandStatus?'Exit ':''}}Advanced Search
Possessing a valley degree of freedom and potential in information processing by manipulating valley features (such as valley splitting), group-VI monolayer transition metal dichalcogenides have attracted enormous interest. This valley splitting can be measured based on the difference between the peak energies of σ+ and σ- polarized emissions for excitons or trions in direct band gap monolayer transition metal dichalcogenides under perpendicular magnetic fields. In this work, a well-prepared heterostructure is formed by transferring exfoliated WSe2 onto a EuS substrate. Circular-polarization-resolved photoluminescence spectroscopy, one of the most facile and intuitive methods, is used to probe the difference of the gap energy in two valleys under an applied out-of-plane external magnetic field. Our results indicate that valley splitting can be enhanced when using a EuS substrate, as compared to a SiO2/Si substrate. The enhanced valley splitting of the WSe2/EuS heterostructure can be understood as a result of an interfacial magnetic exchange field originating from the magnetic proximity effect. The value of this magnetic exchange field, based on our estimation, is approximately 9 T. Our findings will stimulate further studies on the magnetic exchange field at the interface of similar heterostructures.
Radisavljevic, B.; Radenovic, A.; Brivio, J.; Giacometti, V.; Kis, A. Single-layer MoS2 transistors. Nat. Nanotechnol. 2011, 6, 147–150.
Jariwala, D.; Sangwan, V. K.; Lauhon, L. J.; Marks, T. J.; Hersam, M. C. Emerging device applications for semiconducting two-dimensional transition metal dichalcogenides. ACS Nano 2014, 8, 1102–1120.
Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S. Electronics and optoelectronics of twodimensional transition metal dichalcogenides. Nat. Nanotechnol. 2012, 7, 699–712.
Lopez-Sanchez, O.; Lembke, D.; Kayci, M.; Radenovic, A.; Kis, A. Ultrasensitive photodetectors based on monolayer MoS2. Nat. Nanotechnol. 2013, 8, 497–501.
Xu, X. D.; Yao, W.; Xiao, D.; Heinz, T. F. Spin and pseudospins in layered transition metal dichalcogenides. Nat. Phys. 2014, 10, 343–350.
Peimyoo, N.; Shang, J. Z.; Cong, C. X.; Shen, X. N.; Wu, X. Y.; Yeow, E. K. L.; Yu, T. Nonblinking, intense twodimensional light emitter: Monolayer WS2 triangles. ACS Nano 2013, 7, 10985–10994.
Young, A. F.; Sanchez-Yamagishi, J. D.; Hunt, B.; Choi, S. H.; Watanabe, K.; Taniguchi, T.; Ashoori, R. C.; Jarillo-Herrero, P. Tunable symmetry breaking and helical edge transport in a graphene quantum spin Hall state. Nature 2014, 505, 528–532.
Cai, T. Y.; Yang, S. A.; Li, X.; Zhang, F.; Shi, J. R.; Yao, W.; Niu, Q. Magnetic control of the valley degree of freedom of massive Dirac fermions with application to transition metal dichalcogenides. Phys. Rev. B 2013, 88, 115140.
Wu, S. F.; Ross, J. S.; Liu, G. B.; Aivazian, G.; Jones, A.; Fei, Z. Y.; Zhu, W. G.; Xiao, D.; Yao, W.; Cobden, D. et al. Electrical tuning of valley magnetic moment through symmetry control in bilayer MoS2. Nat. Phys. 2013, 9, 149–153.
Sun, L. F.; Yan, J. X.; Zhan, D.; Liu, L.; Hu, H. L.; Li, H.; Tay, B. K.; Kuo, J. L.; Huang, C. C.; Hewak, D. W. et al. Spin-orbit splitting in single-layer MoS2 revealed by triply resonant Raman scattering. Phys. Rev. Lett. 2013, 111, 126801.
Zeng, H. L.; Dai, J. F.; Yao, W.; Xiao, D.; Cui, X. D. Valley polarization in MoS2 monolayers by optical pumping. Nat. Nanotechnol. 2012, 7, 490–493.
Sie, E. J.; McIver, J.; Lee, Y. H.; Fu, L.; Kong, J.; Gedik, N. Valley-selective optical Stark effect in monolayer WS2. Nat. Mater. 2015, 14, 290–294.
Zeng, H. L.; Cui, X. D. An optical spectroscopic study on two-dimensional group-VI transition metal dichalcogenides. Chem. Soc. Rev. 2015, 44, 2629–2642.
Mak, K. F.; He, K. L.; Shan, J.; Heinz, T. F. Control of valley polarization in monolayer MoS2 by optical helicity. Nat. Nanotechnol. 2012, 7, 494–498.
Yao, W.; Xiao, D.; Niu, Q. Valley-dependent optoelectronics from inversion symmetry breaking. Phys. Rev. B 2008, 77, 235406.
Aivazian, G.; Gong, Z. R.; Jones, A. M.; Chu, R. L.; Yan, J.; Mandrus, D. G.; Zhang, C. W.; Cobden, D.; Yao, W.; Xu, X. Magnetic control of valley pseudospin in monolayer WSe2. Nat. Phys. 2015, 11, 148–152.
MacNeill, D.; Heikes, C.; Mak, K. F.; Anderson, Z.; Kormányos, A.; Zólyomi, V.; Park, J.; Ralph, D. C. Breaking of valley degeneracy by magnetic field in monolayer MoSe2. Phys. Rev. Lett. 2015, 114, 037401.
Li, Y. L.; Ludwig, J.; Low, T.; Chernikov, A.; Cui, X.; Arefe, G.; Kim, Y. D.; van der Zande, A. M.; Rigosi, A.; Hill, H. M. et al. Valley splitting and polarization by the Zeeman effect in monolayer MoSe2. Phys. Rev. Lett. 2014, 113, 266804.
Arora, A.; Schmidt, R.; Schneider, R.; Molas, M. R.; Breslavetz, I.; Potemski, M.; Bratschitsch, R. Valley Zeeman splitting and valley polarization of neutral and charged excitons in monolayer MoTe2 at high magnetic fields. Nano Lett. 2016, 16, 3624–3629.
Mitioglu, A. A.; Plochocka, P.; Granados del Aguila, A.; Christianen, P. C. M.; Deligeorgis, G.; Anghel, S.; Kulyuk, L.; Maude, D. K. Optical investigation of monolayer and bulk tungsten diselenide (WSe2) in high magnetic fields. Nano Lett. 2015, 15, 4387–4392.
Stier, A. V.; McCreary, K. M.; Jonker, B. T.; Kono, J.; Crooker, S. A. Exciton diamagnetic shifts and valley Zeeman effects in monolayer WS2 and MoS2 to 65 Tesla. Nat. Commun. 2016, 7, 10643.
Wei, P.; Lee, S.; Lemaitre, F.; Pinel, L.; Cutaia, D.; Cha, W.; Katmis, F.; Zhu, Y.; Heiman, D.; Hone, J. et al. Strong interfacial exchange field in the graphene/EuS heterostructure. Nat. Mater. 2016, 15, 711–716.
Zhao, C.; Norden, T.; Zhang, P. Y.; Zhao, P. Q.; Cheng, Y. C.; Sun, F.; Parry, J. P.; Taheri, P.; Wang, J. Q.; Yang, Y. H. et al. Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field. Nat. Nanotechnol. 2017, 12, 757–762.
Xiao, D.; Liu, G. B.; Feng, W. X.; Xu, X. D.; Yao, W. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 2012, 108, 196802.
Wang, G.; Bouet, L.; Glazov, M. M.; Amand, T.; Ivchenko, E. L.; Palleau, E.; Marie, X.; Urbaszek, B. Magneto-optics in transition metal diselenide monolayers. 2D Mater. 2015, 2, 034002.
Li, H.; Lu, G.; Wang, Y. L.; Yin, Z. Y.; Cong, C. X.; He, Q. Y.; Wang, L.; Ding, F.; Yu, T.; Zhang, H. Mechanical exfoliation and characterization of single- and few-layer nanosheets of WSe2, TaS2, and TaSe2. Small 2013, 9, 1974–1981.
Sahin, H.; Tongay, S.; Horzum, S.; Fan, W.; Zhou, J.; Li, J.; Wu, J.; Peeters, F. M. Anomalous Raman spectra and thickness-dependent electronic properties of WSe2. Phys. Rev. B 2013, 87, 165409.
Rice, C.; Young, R. J.; Zan, R.; Bangert, U.; Wolverson, D.; Georgiou, T.; Jalil, R.; Novoselov, K. S. Raman-scattering measurements and first-principles calculations of straininduced phonon shifts in monolayer MoS2. Phys. Rev. B 2013, 87, 081307.
Wang, Y. L.; Cong, C. X.; Yang, W. H.; Shang, J. Z.; Peimyoo, N.; Chen, Y.; Kang, J. Y.; Wang, J. P.; Huang, W.; Yu, T. Strain-induced direct–indirect bandgap transition and phonon modulation in monolayer WS2. Nano Res. 2015, 8, 2562–2572.
Liu, Q.; Peng, F. Elasticity and thermodynamic properties of EuS related to phase transition. Chin. J. Chem. Phys. 2014, 27, 387–393.
Morell, N.; Reserbat-Plantey, A.; Tsioutsios, I.; Schadler, K. G.; Dubin, F.; Koppens, F. H.; Bachtold, A. High quality factor mechanical resonators based on WSe2 monolayers. Nano Lett. 2016, 16, 5102–5108.
Tada, H.; Kumpel, A. E.; Lathrop, R. E.; Slanina, J. B.; Nieva, P.; Zavracky, P.; Miaoulis, I. N.; Wong, P. Y. Thermal expansion coefficient of polycrystalline silicon and silicon dioxide thin films at high temperatures. J. Appl. Phys. 2000, 87, 4189–4193.
Chakraborty, B.; Bera, A.; Muthu, D. V. S.; Bhowmick, S.; Waghmare, U. V.; Sood, A. K. Symmetry-dependent phonon renormalization in monolayer MoS2 transistor. Phys. Rev. B 2012, 85, 161403.
Müller, N.; Eckstein, W.; Heiland, W.; Zinn, W. Electron spin polarization in field emission from EuS-coated tungsten tips. Phys. Rev. Lett. 1972, 29, 1651–1654.
Britnell, L.; Ribeiro, R. M.; Eckmann, A.; Jalil, R.; Belle, B. D.; Mishchenko, A.; Kim, Y. J.; Gorbachev, R. V.; Georgiou, T.; Morozov, S. V. et al. Strong light-matter interactions in heterostructures of atomically thin films. Science 2013, 340, 1311–1314.
Tosun, M.; Chuang, S.; Fang, H.; Sachid, A. B.; Hettick, M.; Lin, Y. J.; Zeng, Y. P.; Javey, A. High-gain inverters based on WSe2 complementary field-effect transistors. ACS Nano 2014, 8, 4948–4953.
Srivastava, A.; Sidler, M.; Allain, A. V.; Lembke, D. S.; Kis, A.; Imamoğlu, A. Valley Zeeman effect in elementary optical excitations of monolayer WSe2. Nat. Phys. 2015, 11, 141–147.
Jones, A. M.; Yu, H. Y.; Ghimire, N. J.; Wu, S. F.; Aivazian, G.; Ross, J. S.; Zhao, B.; Yan, J. Q.; Mandrus, D. G.; Xiao, D. et al. Optical generation of excitonic valley coherence in monolayer WSe2. Nat. Nanotechnol. 2013, 8, 634–638.
Huang, J.; Hoang, T. B.; Mikkelsen, M. H. Probing the origin of excitonic states in monolayer WSe2. Sci. Rep. 2016, 6, 22414.
You, Y. M.; Zhang, X. -X.; Berkelbach, T. C.; Hybertsen, M. S.; Reichman, D. R.; Heinz, T. F. Observation of biexcitons in monolayer WSe2. Nat. Phys. 2015, 11, 477–481.
Desai, S. B.; Seol, G.; Kang, J. S.; Fang, H.; Battaglia, C.; Kapadia, R.; Ager, J. W.; Guo, J.; Javey, A. Strain-induced indirect to direct bandgap transition in multilayer WSe2. Nano Lett. 2014, 14, 4592–4597.
Yun, W. S.; Han, S. W.; Hong, S. C.; Kim, I. G.; Lee, J. D. Thickness and strain effects on electronic structures of transition metal dichalcogenides: 2H-MX2 semiconductors (M = Mo, W; X = S, Se, Te). Phys. Rev. B 2012, 85, 033305.
京公网安备11010802044758号