| 81. |
- Luo, Yang, et al.
(författare)
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Three-dimensional and temperature-dependent electronic structure of the heavy-fermion compound CePt2In7 studied by angle-resolved photoemission spectroscopy
- 2020
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Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 101:11
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Tidskriftsartikel (refereegranskat)abstract
- The three-dimensional and temperature-dependent electronic structures of the heavy-fermion superconductor CePt2In7 are investigated. Angle-resolved photoemission spectroscopy using variable photon energy establishes the existence of quasi-two- and three-dimensional Fermi surface topologies. Temperature-dependent 4d-4f on-resonance photoemission spectroscopies data reveal that heavy quasiparticle bands begin to form at a temperature well above the characteristic (coherence) temperature T+. The emergence of low-lying crystal electric field excitation may be responsible for the "relocalization" or the precursor to the establishment of heavy electrons coherence in heavy-fermion compounds. These findings provide critical insight into understanding the hybridization in heavy-fermion systems.
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| 82. |
- Meng, Mengmeng, et al.
(författare)
-
Strong spin-orbit interaction and magnetotransport in semiconductor Bi2O2Se nanoplates
- 2018
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 10:6, s. 2704-2710
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor Bi2O2Se nanolayers of high crystal quality have been realized via epitaxial growth. These two-dimensional (2D) materials possess excellent electron transport properties with potential application in nanoelectronics. It is also strongly expected that the 2D Bi2O2Se nanolayers can be an excellent material platform for developing spintronic and topological quantum devices if the presence of strong spin-orbit interaction in the 2D materials can be experimentally demonstrated. Herein, we report the experimental determination of the strength of spin-orbit interactions in Bi2O2Se nanoplates through magnetotransport measurements. The nanoplates are epitaxially grown by chemical vapor deposition, and the magnetotransport measurements are performed at low temperatures. The measured magnetoconductance exhibits a crossover behavior from weak antilocalization to weak localization at low magnetic fields with increasing temperature or decreasing back gate voltage. We have analyzed this transition behavior of magnetoconductance based on an interference theory, which describes quantum correction to the magnetoconductance of a 2D system in the presence of spin-orbit interaction. Dephasing length and spin relaxation length are extracted from the magnetoconductance measurements. Compared to the case of other semiconductor nanostructures, the extracted relatively short spin relaxation length of ∼150 nm indicates the existence of a strong spin-orbit interaction in Bi2O2Se nanolayers.
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| 83. |
- Meng, Mengmeng, et al.
(författare)
-
Universal conductance fluctuations and phase-coherent transport in a semiconductor Bi2O2Se nanoplate with strong spin-orbit interaction
- 2019
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 11:22, s. 10622-10628
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Tidskriftsartikel (refereegranskat)abstract
- We report on phase-coherent transport studies of a Bi2O2Se nanoplate and on observation of universal conductance fluctuations and spin-orbit interaction induced reduction in fluctuation amplitude in the nanoplate. Thin-layered Bi2O2Se nanoplates are grown by chemical vapor deposition (CVD) and transport measurements are made on a Hall-bar device fabricated from a CVD-grown nanoplate. The measurements show weak antilocalization at low magnetic fields at low temperatures, as a result of spin-orbit interaction, and a crossover toward weak localization with increasing temperature. Temperature dependences of characteristic transport lengths, such as spin relaxation length, phase coherence length, and mean free path, are extracted from the low-field measurement data. Universal conductance fluctuations are visible in the low-temperature magnetoconductance over a large range of magnetic fields and the phase coherence length extracted from the autocorrelation function is consistent with the result obtained from the weak localization analysis. More importantly, we find a strong reduction in amplitude of the universal conductance fluctuations and show that the results agree with the analysis assuming strong spin-orbit interaction in the Bi2O2Se nanoplate.
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