A dielectric superfluid of polar molecules
نویسندگان
چکیده
We show that, under achievable experimental conditions, a Bose–Einstein condensate of polar molecules can exhibit dielectric character. In particular, we derive a set of self-consistent mean-field equations that couple the condensate density to its electric dipole field, leading to the emergence of polarization modes that are coupled to the rich quasi-particle spectrum of the condensate. While the usual roton instability is suppressed in this system, the coupling can give rise to a phonon-like instability that is characteristic of a dielectric material with a negative static dielectric function. The electrical properties of any material are encoded in its dielectric function κ(q, ω), which relates the induced dipole moments within the material to an applied electric field with wave vector q and frequency ω. For its predicted relationship to a variety of novel physical phenomena, the possibility of κ taking on negative values has generated much interest. For the ac case, it is well known that the dielectric function can become negative, for example, at frequencies near an atomic resonance, resulting in the high reflectivity of metals [1]. Similarly, under specially engineered circumstances the magnetic permeability of certain materials can become negative, resulting in a negative index of refraction [2, 3]. For a dc field, however, the existence of a negative dielectric function becomes more subtle. Formally, in the infinite-wavelength limit q→ 0, a material is stabilized only if its dielectric function, or constant, is non-negative [4]. Such is not necessarily the case for q 6= 0, however, where the dielectric constant may take on negative values without violating causality [5]. 3 Author to whom any correspondence should be addressed. New Journal of Physics 14 (2012) 043018 1367-2630/12/043018+12$33.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
منابع مشابه
Novel p-wave superfluids of fermionic polar molecules
Recently suggested subwavelength lattices offer remarkable prospects for the observation of novel superfluids of fermionic polar molecules. It becomes realistic to obtain a topological p-wave superfluid of microwave-dressed polar molecules in 2D lattices at temperatures of the order of tens of nanokelvins, which is promising for topologically protected quantum information processing. Another fo...
متن کاملAb Initio Studies of Rotation and Solvent Effects for two important membrane molecules: DPPC and DMPC
DPPC (dipalmitoylphosphatidylcholine) and DMPC (dimyristoylphosphatidylcholine) are taken asphospholipids with an equal polar heads and with the difference in the length of hydrocarbonchains. Results obtain from the structural optimization of the isolated DPPC and DMPC in the gasphase, at the Hartree-Fock level of theory by means of STO-3g,3-21G, 6-31G and 6-31G* basissets. the most important d...
متن کاملStudy of Structural Properties of Polar Liquids in Binary Mixture Using Microwave Techniques
The study of dielectric relaxation properties in the binary mixture of polar molecules has been carried out at 25oC temperature for 11 different concentrations using time domain reflectometry technique. The dielectric properties of solute-solvent mixture in the microwave frequency range of 10MHz to 30GHz gives information about the formation of monomers and multimers as well as interaction betw...
متن کاملInterlayer superfluidity in bilayer systems of fermionic polar molecules.
We consider fermionic polar molecules in a bilayer geometry where they are oriented perpendicularly to the layers, which permits both low inelastic losses and superfluid pairing. The dipole-dipole interaction between molecules of different layers leads to the emergence of interlayer superfluids. The superfluid regimes range from BCS-like fermionic superfluidity with a high Tc to Bose-Einstein (...
متن کامل