Particle-hole character of the Higgs and Goldstone modes in strongly-interacting lattice bosons

We study the low-energy excitations of the Bose-Hubbard model in the strongly-interacting superfluid phase using a Gutzwiller approach and extract the single-particle and single-hole excitation amplitudes for each mode. We report emergent mode-dependent particle-hole symmetry on specific arc-shaped lines in the phase diagram connecting the well-known Lorentz-invariant limits of the Bose-Hubbard model. By tracking the in-phase particle-hole symmetric oscillations of the order parameter, we provide an answer to the long-standing question about the fate of the pure amplitude Higgs mode away from the integer-density critical point. Furthermore, we point out that out-of-phase oscillations are responsible for a full suppression of the condensate density oscillations of the gapless Goldstone mode. Possible detection protocols are also discussed.Comment: 6 pages, 3 figure

High Tc Superconductors -- A Variational Theory of the Superconducting State

We use a variational approach to gain insight into the strongly correlated d-wave superconducting state of the high Tc cuprates at T=0. We show that strong correlations lead to qualitatively different trends in pairing and phase coherence: the pairing scale decreases monotonically with hole doping while the SC order parameter shows a non-monotonic dome. We obtain detailed results for the doping-dependence of a large number of experimentally observable quantities, including the chemical potential, coherence length, momentum distribution, nodal quasiparticle weight and dispersion, incoherent features in photoemission spectra, optical spectral weight and superfluid density. Most of our results are in remarkable quantitative agreement with existing data and some of our predictions, first reported in Phys. Rev. Lett. {\bf 87}, 217002 (2001), have been recently verified.Comment: (Minor revisions, 1 figure added, version to appear in PRB) 23 RevTeX pages, 11 eps figs, long version of cond-mat/0101121, contains detailed comparisons with experiments, analytical insights, technical aspects of the calculation, and comparison with slave boson MF

Dielectric properties of amino substituted pyridines in dilute solutions of some non-polar solvents at different temperatures

Microwave dielectric absorption and relaxation behaviour of each of 2-aminopyridine and 4-dimethylaminopyridine in non-polar solvents benzene, carbon tetrachloride and 1,4-dioxane have been studied at 303.15 K, 313.15 K and 323.15 K temperatures. X-band microwave bench operating at 9.1 GHz has been used for determination of dielectric constant (ε') and dielectric loss (ε"). The static permittivity (ε0) at 2 MHz and permittivity at optical frequency (ε∞) have also been determined. The measured values of dielectric permittivity (ε') and dielectric loss (ε") have been used to evaluate relaxation time (τ), dipole moment (μ), molar volume (Vm) and molar polarization of solute (P2). Present study suggests the existence of intra-molecular and overall rotation of the amino pyridine molecules in the non-polar solvents. The solute–solvent molecular associations have been predicted. The effect of solvent environments on the relaxation behaviour of the amino pyridines has also been discussed

Pairing and superconductivity driven by strong quasiparticle renormalization in two-dimensional organic charge transfer salts

We introduce and analyze a variational wave function for quasi two-dimensional kappa-ET organic salts containing strong local and nonlocal correlation effects. We find an unconventional superconducting ground state for intermediate charge carrier interaction, sandwiched between a conventional metal at weak coupling and a spin liquid at larger coupling. Most remarkably, the excitation spectrum is dramatically renormalized and is found to be the driving force for the formation of the unusual superconducting state.Comment: 4 pages, 4 figure

Chronic recurrent priapism: A high flow state secondary to an arteriovenous fistula of the corpus cavernosum

Priapism is clinically defined as an erect penis for more than 4h unrelated to sexual stimulation. There are two main types of priapism-high flow and low flow, based on the pathophysiology. In this case report we will mainly focus on high flow, non-ischemic priapism, which is the less common form. High flow priapism occurs secondary to congenital malformation or from the development of arteriovenous malformation from genital trauma. This case highlights the importance of differentiation and recognition of posttraumatic high flow priapism and unveils the role of selective internal pudendal artery angiography and embolization in its management

Orientational and dielectric behaviour of N, N-dimethylformamide in different non-polar solvents

Dielectric behaviour of concentrated solutions of different mole fractions of N, N-dimethylformamide in various non-polar solvents has been studied using precision LCR meter with four terminal liquid dielectric test fixture over a frequency range 20 Hz to 2 MHz at 303.15 K temperature. The dielectric parameters namely dielectric constant (ε′), dielectric loss (ε″) and static dielectric constant (ε0) have been determined by capacitive measurement method. The limiting dielectric constant (ε∞) has been determined by Abbe’s refractometer for the same solutions at 303.15 K temperature. Kirkwood correlation factor geff has also been calculated using determined values of ε0 and ε∞,to gain information about the orientational behaviour of N, N-dimethylformamide in different non-polar solvent environments