Antiferromagnetism at the YBa2Cu3O7/La2/3Ca1/3MnO3 interface

Refraction at the Interface of a Lossy Metamaterial

The refraction phenomenon at the interface of an ordinary material and a lossy metamaterial has been investigated. For oblique incidence on the lossy metamaterial, the planes of constant amplitude of the refracted wave are parallel to the interface and the plane of constant phases make a real angle with the interface (real refraction angle). The real refraction angle and hence, the real refract...

Unconventional resistivity at the border of metallic antiferromagnetism in NiS2

We report low-temperature and high-pressure measurements of the electrical resistivity T of the antiferromagnetic compound NiS2 in its high-pressure metallic state. The form of T , p suggests the presence of a quantum phase transition at a critical pressure pc=76 5 kbar. Near pc, the temperature variation of T is similar to that observed in NiS2−xSex near the critical composition x=1, where met...

Antiferromagnetism with Ultracold Atoms

We use ultracold spin–1/2 atomic fermions (Li) to realize the Hubbard model on a three-dimensional (3D) optical lattice. At relatively high temperatures and at densities near half-filling, we show that the gas forms a Mott insulator with unordered spins. To observe antiferromagnetic order that is predicted to occur at lower temperatures, we developed the compensated optical lattice method to ev...

Entangling Superconductivity and Antiferromagnetism

Antiferromagnetism of the 2D Hubbard Model at Half Filling: Analytic Ground State at Weak Coupling

r n̂r↑n̂r↓. In Shf we study the many-body eigenstates of the kinetic energy with vanishing eigenvalue of the Hubbard repulsion (W = 0 states). In the Sz = 0 sector, this is a N times degenerate multiplet. From the singlet component one obtains the ground state of the Hubbard model for U = 0, which is unique in agreement with a theorem by Lieb. The wave function demonstrates an antiferromagnetic o...