We study the Ginzburg-Landau free energy functional for two coupled U(1) charge order parameters describing two nonequivalent charge orders with wave vector Q detected in x-ray and STM measurements of underdoped cuprates. We do not rely on a mean-field analysis, but rather utilize a field-theoretical technique suitable to study the interplay between vortex physics and discrete symmetry breaking in two-dimensional systems with U(1) symmetry. Our calculations support the idea that in the clean systems there are two transitions: from a high-temperature disordered state into a state with a composite charge order which breaks time-reversal symmetry, but leaves U(1) fields disordered, and then into a state with quasi-long-range order in the U(1) fields.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - May 30 2014|