Avoiding Stripe Order: Emergence of the Supercooled Electron Liquid

Abstract

In the absence of disorder, electrons can display glassy behavior through supercooling the liquid state, avoiding the solidification into a charge ordered state. Such supercooled electron liquids are experimentally found in organic θ-M M compounds. We present theoretical results that qualitatively capture the experimental findings. At intermediate temperatures, the conducting state crosses over into a weakly insulating pseudogap phase. The stripe order phase transition is first order, so that the liquid phase is metastable below T s . In the supercooled liquid phase the resistivity increases further and the density of states at the Fermi level is suppressed, indicating kinetic arrest and the formation of a glassy state. Our results are obtained using classical Extended Dynamical Mean Field Theory.

Suppressed density of states in self-generated Coulomb glasses

“…Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. glassy behavior of electrons in the θ-organic compounds [16,17]. We find a remarkable agreement between our analytical form of the DOSs and the numerical results.…”

“…In this Letter, our considerations and analysis centered on the zero-temperature ensemble of metastable states. At finite temperature the gap will be filled, and earlier results are consistent with an exponentially weak scaling at finite temperature,  =~--( ) ( ) g T T V T 0, exp 1 2 [17]. Again, notice the relative stability compared to systems with quenched disorder where g(ò=0, T)∼T [30,31].…”

“…We proposed that self-generated glasses with Coulomb interactions have an exponentially suppressed density of states, following equation (11). This relation is satisfied in a simple model of particles on a triangular lattice that was shown earlier to form a glass [16,17].…”

“…We start by numerically studying the ensemble of metastable states for the model of particles on a half-filled ( = n 1 2) triangular lattice of size N=L 2 with periodic boundary conditions, introduced in [16,17] and in equation (1). The interaction potential contains both a Coulomb tail and nearest-neighbor repulsion, tunable by the parameter x,…”

Critical behavior of the two-dimensional Coulomb glass at zero temperature

“…The lifting of degeneracy is also accompanied by emergence of very many low lying metastable states with amorphous "stripe-glass" spatial structure 42 . Extended Dynamical Mean Field calculations show that the ground state has stripe order and a first order transition is observed from liquid to stripe ordered phase as temperature is lowered 43 . In our case, there is two fold degeneracy in COP in absence of disorder which is lifted by random fields.…”