Srinivas Raghu

Analogs of quantum-Hall-effect edge states in photonic crystals

Photonic crystals built with time-reversal-symmetry-breaking Faraday-effect media can exhibit chiral edge modes that propagate unidirectionally along boundaries across which the Faraday axis reverses. These modes are precise analogs of the electronic edge states of quantum-Hall-effect (QHE) systems, and are also immune to backscattering and localization by disorder. The Berry curvature of the photonic bands plays a role analogous to that of the magnetic field in the QHE. Explicit calculations demonstrating the existence of such unidirectionally propagating photonic edge states are presented.

Time-reversal-invariant topological superconductors and superfluids in two and three dimensions

We construct time reversal invariant topological superconductors and superfluids in two and three dimensions which are analogous to the recently discovered quantum spin Hall and three-d Z2 topological insulators respectively. These states have a full pairing gap in the bulk, gapless counterpropagating Majorana states at the boundary, and a pair of Majorana zero modes associated with each vortex. We show that the time reversal symmetry naturally emerges as a supersymmetry, which changes the parity of the fermion number associated with each time-reversal invariant vortex. In the presence of external T-breaking fields, non-local topological correlation is established among these fields, which is an experimentally observable manifestation of the emergent supersymmetry.

Minimal two-band model of the superconducting iron oxypnictides

Following the discovery of the Fe-pnictide superconductors, local-density approximation (LDA) band structure calculations showed that the dominant contributions to the spectral weight near the Fermi energy came from the

Superconductivity in the repulsive Hubbard model: an asymptotically exact weak-coupling solution

\text{Fe}\text{ }3d

Hidden quasi-one-dimensional superconductivity in Sr₂RuO₄.

orbitals. The Fermi surface is characterized by two hole surfaces around the

Majorana zero modes in a quantum Ising chain with longer-ranged interactions

\ensuremath{\Gamma}

Non-Fermi liquid fixed point in a Wilsonian theory of quantum critical metals

point and two electron surfaces around the

Theory of the three-dimensional quantum Hall effect in graphite.

M

Effects of longer-range interactions on unconventional superconductivity

point of the two Fe/cell Brillouin zone. Here, we describe a two-band model that reproduces the topology of the LDA Fermi surface and exhibits both ferromagnetic and

Nernst effect and diamagnetism in phase fluctuating superconductors

q=(\ensuremath{\pi},0)