scholarly journals Prediction of intrinsic topological superconductivity in Mn-doped GeTe monolayer from first-principles

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaoming Zhang ◽  
Kyung-Hwan Jin ◽  
Jiahao Mao ◽  
Mingwen Zhao ◽  
Zheng Liu ◽  
...  
Keyword(s):  
First Principles ◽  
Magnetic Semiconductor ◽  
Zeeman Splitting ◽  
Hole Doping ◽  
Limit Transition ◽  
Topological Superconductors ◽  
Class D ◽  
Electron Phonon Coupling ◽  
Mn Concentration ◽  
Mn Doped

AbstractThe recent discovery of topological superconductors (TSCs) has sparked enormous interest. The realization of TSC requires a delicate tuning of multiple microscopic parameters, which remains a great challenge. Here, we develop a first-principles approach to quantify realistic conditions of TSC by solving self-consistently Bogoliubov-de Gennes equation based on a Wannier function construction of band structure, in presence of Rashba spin-orbit coupling, Zeeman splitting and electron-phonon coupling. We further demonstrate the power of this method by predicting the Mn-doped GeTe (Ge1-xMnxTe) monolayer—a well-known dilute magnetic semiconductor showing superconductivity under hole doping—to be a Class D TSC with Chern number of −1 and chiral Majorana edge modes. By constructing a first-principles phase diagram in the parameter space of temperature and Mn concentration, we propose the TSC phase can be induced at a lower-limit transition temperature of ~40 mK and the Mn concentration of x~0.015%. Our approach can be generally applied to TSCs with a phonon-mediated pairing, providing useful guidance for future experiments.

First-Principles Approach to Mn-Doped Group IV Semiconductors: Comparison with Experiments and Outlook

2006 ◽  
Vol 52 ◽  
pp. 11-20
Author(s):  
Alessandra Continenza ◽  
Silvia Picozzi ◽  
Gianni Profeta ◽  
Luca Ottaviano ◽  
Maurizio Passacantando ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Magnetic Semiconductor ◽  
Group Iv ◽  
High Integrability ◽  
Group Iv Semiconductors ◽  
Ge Matrix ◽  
Small Clusters ◽  
Mn Doped ◽  
Comparison With Experiments

We present an extensive theoretical and experimental study of the Mn-Ge dilute magnetic semiconductor, a material which - due to its high integrability with mainstream Si technology - may hold good promises for spintronic applications. Ab-initio calculations on several different systems containing isolated Mn impurities as well as small clusters (up to three Mn impurities) show that Mn has a tendency to segregate into the Ge matrix and to stabilize occupation of interstitial sites if these are coordinated with other Mn occupying substitutional sites nearby. Several different experimental characterizations (HRTEM, XRD, UPS, MOKE) performed on Mn ion-implanted systems are analyzed and discussed: a close comparison betweeen experimental evidences and density functional calculations allows a full understanding of the sample properties and to disentagle the contributions coming from the diluted and segregated phases. The complexity of this system shows that much has to be done still to understand the physics of these materials and to undisclose all their possible applications.

First-principles prediction of superconductivity in LiBSi1-xAlx

2015 ◽  
Vol 29 (12) ◽  
pp. 1550064
Author(s):  
Rende Miao ◽  
Jun Yang ◽  
Zhong Bai ◽  
Dan Can ◽  
Xi Zhang ◽  
...  
Keyword(s):  
First Principles ◽  
Partial Substitution ◽  
Hole Doping ◽  
Superconducting Transition ◽  
Coupling Constant ◽  
Superconducting Properties ◽  
Virtual Crystal Approximation ◽  
Phonon Spectra ◽  
Electron Phonon Coupling ◽  
Formation Energies

Electronic structure, lattice dynamics and superconducting properties for theoretically devised superconductor LiBSi 1-x Al x are obtained by first-principles calculations. We assume that Lithium Boron Silicon ( LiBSi ) has the same crystal structure as that of Lithium borocarbide ( LiBC ). The pristine LiBSi is predicted to be a zero-gap semiconductor. Hole doping of LiBSi through partial substitution of Si by SiAl atoms can produce a semiconductor–metal transition and develop superconductivity. To assess the thermodynamic stability of LiBSi 1-x Al x, the formation energies are calculated using the supercell method. For LiBSi 0.75 Al 0.25 and LiBSi 0.875 Al 0.125, the obtained formation energies are -5.9 and -6.1 eV, respectively, indicating that LiBSi 1-x Al x is energetically favorable at least in the range of 0 ≤ x ≤ 0.25. Phonon spectra and superconducting properties are obtained within the virtual-crystal approximation (VCA) treatment. The results show that LiBSi 1-x Al x is dynamically stable approximately in the range of 0 ≤ x ≤ 0.35. For LiBSi 0.8 Al 0.2, the obtained electron-phonon coupling constant λ is 0.86 and superconducting transition temperature TC is predicted to be in the range of 11–13 K (0.14 ≥ μ* ≥ 0.1).

Novel Ferromagnetic Mn-Doped ZnSiAs2 Chalcopyrite with Curie Point Exceeded Room Temperature

2009 ◽  
Vol 152-153 ◽  
pp. 311-314 ◽  
Author(s):  
S.F. Marenkin ◽  
V.M. Novotortsev ◽  
I.V. Fedorchenko ◽  
S.A. Varnavskiy ◽  
L.A. Koroleva ◽  
...  
Keyword(s):  
Curie Temperature ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Magnetic Semiconductor ◽  
Ferromagnetic Phase ◽  
Superparamagnetic Clusters ◽  
Magnetic Resistance ◽  
P Type ◽  
Mn Concentration ◽  
Mn Doped

Based on Mn-doped chalcopyrite ZnSiAs2 the new dilute magnetic semiconductor with p-type conductivity was produced. The Curie temperature behavior of the produced semiconductor is distinctly dependent on the Mn concentration: 325 K for 1 wt.% and 337 K for 2 wt.% of Mn, consequently. Magnetization, electrical resistance, magnetic resistance and Hall effect of mentioned compositions were studied. Temperature dependence of magnetization M(T) have complicate behavior. For T  15 K the M(T) dependence is characteristic for superparamagnetic and at T > 15 K magnetization is sum of magnetizations of ensemble of superparamagnetic clusters and ferromagnetic phase contained frustration regions.

Electronic and magnetic properties of F atoms adsorbed on TiO2:Mn(001) diluted magnetic semiconductor surfaces: First-principles calculations

2014 ◽  
Vol 28 (18) ◽  
pp. 1450096 ◽  
Author(s):  
Chunlei Wang ◽  
Dan Li ◽  
Yuan Niu ◽  
Hongmin Zhao ◽  
Chunjun Liang
Keyword(s):  
First Principles ◽  
Formation Energy ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Moments ◽  
Magnetic Semiconductor ◽  
First Principles Calculations ◽  
Ion Doping ◽  
Diluted Magnetic ◽  
The Stability ◽  
Mn Doped

We performed first-principles calculations for two Mn -doped structures in which Mn atoms substitute Ti atoms to determine whether (i) it is more conducive to Mn ion doping and (ii) ferromagnetism can occur in F adsorption anatase TiO 2 surfaces. Ferromagnetic (FM) coupling is more stable than antiferromagnetic (AFM) coupling for all doping configurations as the adsorption of F atoms on the surface significantly lowers the formation energy of the TiO 2: Mn system. The magnetic moments of the Mn ions are reduced, whereas those of O atoms on the surface are increased. The magnetic moment of the O atoms is mainly derived from the spin polarization p x and p y orbitals. F adsorption promotes doping of Mn atoms and to a certain extent improves the stability of the structure, magnetism and metallicity.

Electronic Structure and Optical Properties of a Mn-Doped InSe/WSe2 van der Walls Heterostructure: First Principles Calculations

2020 ◽  
Vol 77 (7) ◽  
pp. 587-591
Author(s):  
Rundong Liang ◽  
Xiuwen Zhao ◽  
Guichao Hu ◽  
Weiwei Yue ◽  
Xiaobo Yuan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculations ◽  
Mn Doped

scholarly journals Mn charge states in GaMnN as a function of Mn concentration and co-doping

2007 ◽  
Vol 1040 ◽  
Author(s):  
Enno Malguth ◽  
Axel Hoffmann ◽  
Wolfgang Gehlhoff ◽  
Matthew H. Kane ◽  
Ian T. Ferguson
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Magnetic Semiconductor ◽  
Electron Spin Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Mg Doping ◽  
Co Doping ◽  
Spin Resonance ◽  
P Type ◽  
Mn Concentration

AbstractIn the context of the pursuit of a dilute magnetic semiconductor for spintronic applications, a set of GaMnN samples with varying Mn concentration and Si or Mg co-doping was investigated by optical and electron spin resonance spectroscopy. The results clearly demonstrate how the charge state of Mn is changed between 2+, 3+ and 4+ by Mg and Si co-doping. For p-type GaMnN we show that the introduction of the Mn3+/4+ donor can be compensated by Mg co-doping lowering the Fermi energy below the Mn3+/4+ level. While our results are in agreement with the hypothesis that the infrared photoluminescence appearing in GaMnN upon Mg doping originates from Mn4+, an unambiguous proof is still to be presented. Under this assumption, our measurements show that the Mn4+ center must be excited via an extra-center process at 2.54 eV.

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