scholarly journals Large linear magnetoresistance and evidence of degeneracy lifting of valence bands in rhombohedral phase of topological crystalline insulator SnTe

2021 ◽  
Author(s):  
Sonali Baral ◽  
Mukesh Kumar Dasoundhi ◽  
Indu Rajput ◽  
Devendra Kumar ◽  
Archana Lakhani
Keyword(s):  
Rhombohedral Phase ◽  
Linear Magnetoresistance ◽  
Valence Bands ◽  
Topological Crystalline Insulator

Large linear magnetoresistance in topological crystalline insulator Pb0.6Sn0.4Te

2016 ◽  
Vol 233 ◽  
pp. 199-204 ◽  
Author(s):  
Subhajit Roychowdhury ◽  
Somnath Ghara ◽  
Satya N. Guin ◽  
A. Sundaresan ◽  
Kanishka Biswas
Keyword(s):  
Linear Magnetoresistance ◽  
Topological Crystalline Insulator

Valence electron energy loss spectroscopy in reflection geometry

1989 ◽  
Vol 47 ◽  
pp. 378-379
Author(s):  
J. Liu ◽  
J. M. Cowley
Keyword(s):  
Energy Loss ◽  
Valence Electron ◽  
Interband Transition ◽  
Specular Reflection ◽  
Three Dimensional ◽  
Electron Excitation ◽  
Transmission Electron ◽  
Yield Information ◽  
Valence Bands ◽  
Excitation Processes

The low energy loss region of a EELS spectrum carries information about the valence electron excitation processes (e.g., collective excitations for free electron like materials and interband transitions for insulators). The relative intensities and the positions of the interband transition energy loss peaks observed in EELS spectra are determined by the joint density of states (DOS) of the initial and final states of the excitation processes. Thus it is expected that EELS in reflection mode could yield information about the perturbation of the DOS of the conduction and valence bands of the bulk crystals caused by the termination of the three dimensional periodicity at the crystal surfaces. The experiments were performed in a Philipps 400T transmission electron microscope operated at 120 kV. The reflection EELS spectra were obtained by a Gatan 607 EELS spectrometer together with a Tracor data acquisition system and the resolution of the spectrometer was about 0.8 eV. All the reflection spectra are obtained from the specular reflection spots satisfying surface resonance conditions.

Photoemission study on the valence bands of DMe-DCNQI derived charge-transfer salts

1991 ◽  
Vol 1 (9) ◽  
pp. 1347-1354 ◽  
Author(s):  
D. Schmeißer ◽  
A. Gonzales ◽  
J. U. von Schütz ◽  
H. Wachtel ◽  
H. C. Wolf
Keyword(s):  
Charge Transfer ◽  
Charge Transfer Salts ◽  
Valence Bands ◽  
Photoemission Study

Hybrid Valence Bands in Strained-Layer Heterostructures grown on Relaxed SiGe Virtual Substrates

2003 ◽  
Vol 765 ◽  
Author(s):  
Minjoo L. Lee ◽  
Eugene A. Fitzgerald
Keyword(s):  
Strained Silicon ◽  
Strained Layer ◽  
Dual Channel ◽  
Enhanced Mobility ◽  
Valence Bands ◽  
Almost All

AbstractThe use of alternative channel materials such as germanium [1,2] and strained silicon (ε-Si) [3-5] is increasingly being considered as a method for improving the performance of MOSFETs. While ε-Si grown on relaxed Si1-x Gex is drawing closer to widespread commercialization, it is currently believed that almost all of the performance benefit in CMOS implementations will derive from the enhanced mobility of the n -MOSFET [5]. In this paper, we demonstrate that ε-Si p -MOSFETs can be engineered to exhibit mobility enhancements that increase or remain constant as a function of inversion density. We have also designed and fabricated ε-Si / ε-Ge dual-channel p -MOSFETs exhibiting mobility enhancements of 10 times. These p -MOSFETs can be integrated on the same wafers as ε-Si n -MOSFETs, making symmetric-mobility CMOS possible.

scholarly journals Magnetic crystalline-symmetry-protected axion electrodynamics and field-tunable unpinned Dirac cones in EuIn2As2

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
S. X. M. Riberolles ◽  
T. V. Trevisan ◽  
B. Kuthanazhi ◽  
T. W. Heitmann ◽  
F. Ye ◽  
...  
Keyword(s):  
Density Functional ◽  
Surface States ◽  
Antiferromagnetic Order ◽  
Functional Theory ◽  
Magnetic Symmetry ◽  
Integer Quantum ◽  
Symmetry Protected ◽  
Topological Crystalline Insulator ◽  
Low Symmetry ◽  
Crystalline Symmetry

AbstractKnowledge of magnetic symmetry is vital for exploiting nontrivial surface states of magnetic topological materials. EuIn2As2 is an excellent example, as it is predicted to have collinear antiferromagnetic order where the magnetic moment direction determines either a topological-crystalline-insulator phase supporting axion electrodynamics or a higher-order-topological-insulator phase with chiral hinge states. Here, we use neutron diffraction, symmetry analysis, and density functional theory results to demonstrate that EuIn2As2 actually exhibits low-symmetry helical antiferromagnetic order which makes it a stoichiometric magnetic topological-crystalline axion insulator protected by the combination of a 180∘ rotation and time-reversal symmetries: $${C}_{2}\times {\mathcal{T}}={2}^{\prime}$$ C 2 × T = 2 ′ . Surfaces protected by $${2}^{\prime}$$ 2 ′ are expected to have an exotic gapless Dirac cone which is unpinned to specific crystal momenta. All other surfaces have gapped Dirac cones and exhibit half-integer quantum anomalous Hall conductivity. We predict that the direction of a modest applied magnetic field of μ0H ≈ 1 to 2 T can tune between gapless and gapped surface states.

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