Role of charge doping and strain in the stabilization of in-plane ferromagnetism in monolayer VSe2 at room temperature

Memarzadeh S., Roknabadi M. R., Modarresi M., MOĞULKOÇ A., Rudenko A. N.

2D MATERIALS, cilt.8, sa.3, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 8 Sayı: 3
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1088/2053-1583/abf626
  • Dergi Adı: 2D MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: 2D monolayer, ferromagnetism, VSe2 monolayer, phase transition, density functional theory, TRANSITION-METAL DICHALCOGENIDES, SPIN-WAVE THEORY, 1ST-PRINCIPLES CALCULATIONS, ELECTRONIC-STRUCTURE, CORRELATED SYSTEMS, EXISTENCE, MAGNETISM, ABSENCE, ORIGIN, STATES
  • Ankara Üniversitesi Adresli: Evet

Özet

We study the origin of in-plane ferromagnetism in monolayer VSe2 focusing on the effect of charge doping and mechanical strain. We start from an anisotropic spin Hamiltonian, estimate its parameters from density functional calculations, and determine the spectrum of spin-wave excitations. We show that 1T-VSe2 is characterized by relatively strong on-site Coulomb repulsion (U similar or equal to 5 eV), favoring an antiferromagnetic ground state, which contradicts experimental observations. We calculate the magnetic phase diagram as a function of charge doping and strain, and find a transition to the ferromagnetic state with in-plane easy axis under moderate hole doping (similar to 10(14) cm(-2)). Analysis of spin-wave excitations in doped monolayer VSe2 reveals a gap due to the in-plane anisotropy, giving rise to long-range magnetic order well above 300 K, in agreement with recent experiments. Our findings suggest that experimentally available 1T-VSe2 monolayer samples might be intrinsically or extrinsically doped, which opens up the possibility for a controllable manipulation of their magnetic properties.