2014/10/15 by Wenchen Luo, R. Côté
Materials Science · Physics and Astronomy · #Condensed matter physics #Electron #Ferromagnetism #Graphene research and applications #Ising model #Magnetic field #Physics #Quantum Hall effect #Quantum and electron transport phenomena #Quantum mechanics #Skyrmion #Spin (aerodynamics) #Topological Materials and Phenomena #Zeeman effect #Zeeman energy #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.90.245410
18 pages with 9 eps figures
arxiv created 2014/10/15 · openalex publication_date 2014/12/04 · arxiv updated 2015/03/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The chiral two-dimensional electron gas in Landau levels |N|>0 of a Bernal-stacked graphene bilayer has a valley-pseudospin Ising quantum Hall ferromagnetic behavior at odd filling factors \ensuremathνN=1,3 of these fourfold degenerate states. At zero interlayer electrical bias, the ground state at these fillings is spin polarized and electrons occupy one valley or the other while a finite electrical bias produces a series of valley pseudospin-flip transitions. In this work, we discuss the hysteretic behavior of the Ising quantum Hall ferromagnets. We compute the transport gap due to different excitations: bulk electron-hole pairs, electron-hole pairs confined to the coherent region of a valley-pseudospin domain wall, and spin or valley-pseudospin skyrmion-antiskyrmion pairs. We determine which of these excitations has the lowest energy at a given value of the Zeeman coupling, bias, and magnetic field.