Two general features of a superconductor, which appear at the critical temperature, are the
formation of an energy gap and the expulsion of magnetic flux (the Meissner effect). In …

Since the discovery of high-temperature superconductivity in cop-per oxide compounds1,
there has been much effort to understand what is required for a compound to have a high …

Superconductivity is a striking example of a quantum phenomenon in which electrons move
coherently over macroscopic distances without scattering. The high-temperature …

We present inelastic neutron scattering experiments on a single-domain crystal of lightly
doped La 1.96 Sr 0.04 CuO 4. We find that the magnetic excitation spectrum in this …

La 139 NQR spin-lattice relaxation rates (NSLR) versus temperature are presented for La 2−
x Sr x CuO 4 with x= 0.02–0.08. The NSLR below∼ 2 TN (x) shows a power-law critical …

We report the magnetization M (H, T) of La 2 Cu 1− x Zn x O 4− y for x varying from 0.00 to
0.03. A suppression of the Néel temperature as a function of doping is observed. In contrast …

We report a comprehensive neutron-scattering study of the evolution of the magnetic
excitations in La 2− x Sr x CuO 4 for 0≤ x≤ 0.04. We first present accurate measurements of …

The mechanism of high-transition-temperature (high-T c) superconductivity in doped copper
oxides is an enduring problem. Antiferromagnetism is established as the competing order …

THE fundamental theoretical problem posed by the new high-temperature (high-T,)
superconductors is to understand the microscopic nature of the supercondueting state and …

We have measured the static magnetic susceptibility and the resistivity of Zn (0<~ z<~ 0. 2 5)
and Sr (0<~ x<~ 0. 0 3) doped La 2 CuO 4. Our data clearly show that Zn impurities lead to …