Spin and valley filtering properties in a ferromagnetic 8-pmmn borophene monolayer

• Published in: The Journal of physics and chemistry of solids 2024-05, Vol.188, p.111933, Article 111933
• Main Authors: Bidgoli, Fatemeh Imanian Mofrad, Nikoofard, Hossein, Nikoofard, Narges, Esmaeilzadeh, Mahdi
• Format: Article
• Language: English
• Subjects: Borophene monolayer; Nanoelectronic devices; N–p–n junction; Quantum transport; Spin and valley filters
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2024.111933

We study spin- and valley-dependent transport properties in a n-p–n junction of 8-pmmn borophene monolayer. We show that an exchange magnetic field can generate spin polarization in the system and a gate voltage, as a potential barrier, induces valley polarization. The valley polarization, induced by the gate voltage, is due to the anisotropic and tilted Dirac cones of borophene structure. This property is the advantage of borophene over the other 2D materials with isotropic and non-tilted Dirac cones such as graphene in which a gate potential cannot induce valley polarization. We also show that the proposed device (borophene-based n-p–n junction) can work as perfect spin and perfect valley filters. The spin and valley filters can be controlled by changing the gate voltage and/or Fermi energy. The results of this study show that borophene has a suitable potential to be used in spintronic and valleytronic devices. •Our npn junction can work as perfect spin and perfect valley filters.•Spin-up filter changes to the spin-down filter and vice versa via gate voltage.•Valley filtering by applying gate voltage is due to tilted Dirac cones.•Above property cannot occur in 2D materials with isotropic and non-tilted cones.•Borophene shows a great potential for use in spintronic and valleytronic devices.