New phases of HTS in high magnetic field

Fluctuation behavior of HTS in high magnetic field is studied within the Ginzburg-Landau theory. Landau level degeneracy of Cooper pairs enhances fluctuations which destroy the familiar Abrikosov lattice. Instead, a charge density-wave of Cooper pairs (SCDW) is the new low-temperature phase of the theory. SCDW has no condensate, but differs from the normal state by a periodic modulation of Cooper pair density. In the presence of disorder, the Abrikosov state is revived and both superconducting and density-wave phases are possible.I would like to thank my collaborators I. F. Herbut, R. áik, and D. Stroud for many useful and productive discussions. The work reported here was supported in part by the NSF grant DMR-9415549.