Electronic systems with multiple degenerate degrees of freedom can support a rich variety of
broken symmetry states. In a graphene Landau level (LL), strong Coulomb interactions and …

The quantum Hall (QH) effect in two-dimensional electrons and holes in high quality
graphene samples is studied in strong magnetic fields up to 45 T. QH plateaus at filling …

We report direct measurements of the valley susceptibility, the change of valley population in
response to an applied symmetry-breaking strain, in an AlAs two-dimensional electron …

Starting from the graphene lattice tight-binding Hamiltonian with an on-site U and long-
range Coulomb repulsion, we derive an interacting continuum Dirac theory governing the …

Graphene exhibits quantum Hall ferromagnetism in which an approximate SU (4) symmetry
involving spin and valley degrees of freedom is spontaneously broken. We construct a set of …

Nematic quantum fluids with wave functions that break the underlying crystalline symmetry
can form in interacting electronic systems. We examined the quantum Hall states that arise …

We review the recent developments in electronic Raman scattering measurements of charge
nematic fluctuations in iron-based superconductors. A simple theoretical framework of a d …

The Dirac Hamiltonian, which successfully describes relativistic fermions, applies equally
well to electrons in solids with linear energy dispersion, for example, in bismuth and …

The high magnetic field electronic structure of bilayer graphene is enhanced by the spin,
valley isospin, and an accidental orbital degeneracy, leading to a complex phase diagram of …

Two‐dimensional electrons in AlAs quantum wells occupy multiple conduction‐band minima
at the X‐points of the Brillouin zone. These valleys have large effective mass and g‐factor …