Density ordering instabilities of quasi-two-dimensional fermionic polar molecules in single-layer and multi-layer configurations: exact treatment of exchange interactions
arXiv:1109.3755 · doi:10.1103/PhysRevB.84.235124
Abstract
We study the in-plane and out-of-plane density ordering instabilities of quasi-two-dimensional fermionic polar molecules in single-layer and multi-layer configurations. We locate the soft modes by evaluating linear response functions within the conserving time-dependent Hartree-Fock (TDHF). The short-range exchange effects are taken into account by solving the Bethe-Salpeter integral equation numerically. An instability phase diagram is calculated for both single-layer and multi-layer systems and the unstable wave-vector is indicated. In all cases, the in-plane density wave instability is found to precede the out-of-plane instability. The unstable wave-vector is found to be approximately twice the Fermi wave-vector of one of the subbands at a time and can change discontinuously as a function of density and dipolar interaction strength. In multi-layer configurations, we find a large enhancement of density wave instability driven by dilute quasiparticles in the first excited subband. Finally, we provide a simple qualitative description of the phase diagrams using a RPA-like approach. Compared to previous works done within the RPA approximation, we find that inclusion of exchange interactions stabilize the normal liquid phase further and increase the critical dipolar interaction strength corresponding to the onset of density-wave instability by over a factor of two.
20 pages, 16 figures
References in corpus (19)
- Many-Body Physics with Ultracold Gases
- Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
- A High Phase-Space-Density Gas of Polar Molecules
- Ultracold Molecules in the Ro-Vibrational Triplet Ground State
- Ultracold dense gas of deeply bound heteronuclear molecules
- Reactions of ultracold alkali metal dimers
- Structural phase transitions in low-dimensional ion crystals
- Quantum phases of a Two-Dimensional Dipolar Fermi Gas
- Wigner crystal physics in quantum wires
- Interlayer superfluidity in bilayer systems of fermionic polar molecules
- Strong dependence of ultracold chemical rates on electric dipole moments
- Superfluidity and dimerization in a multilayered system of fermionic polar molecules
- Spontaneous inhomogeneous phases in ultracold dipolar Fermi gases
- Dynamics of ultracold molecules in confined geometry and electric field
- Unrestricted Hartree-Fock theory of Wigner crystals
- Ground state of low dimensional dipolar gases: linear and zigzag chains
- Quantum structural phase transition in chains of interacting atoms
- Quantum phase transition in quantum wires controlled by an external gate
- Collective phenomena in quasi-two-dimensional fermionic polar molecules: band renormalization and excitons
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