Based on a mean field analysis of the Chen-Lubensky model we extend an earlier discussion regardi... more Based on a mean field analysis of the Chen-Lubensky model we extend an earlier discussion regarding the effect of chirality on the region of the phase diagram where the Cholesteric, Smectic-A, and Smectic- C* phases meet (i.e., the N* AC* point). We show that, on the Sm-C* side of the phase diagram, a second twist grain boundary (or chiral smectic)
Bogoliubov theory of Coulomb-coupled [m ↑ m ↓ 0] quantum Hall states. Daniel P. Arovas and Scot R... more Bogoliubov theory of Coulomb-coupled [m ↑ m ↓ 0] quantum Hall states. Daniel P. Arovas and Scot R. Renn Department of Physics, University of California at San Diego, La Jolla, California 92093. Received 4 May 1994 The ...
Recently, Inderees et al. have observed inverse-square-root behavior of specific heat of YBaâCuâO... more Recently, Inderees et al. have observed inverse-square-root behavior of specific heat of YBaâCuâOââ/sub delta/ near T/sub c/ corresponding to Gaussian fluctuations. We analyze their results using the most general Landau theories of superconductivity that are consistent with either orthorhombic or tetragonal crystal symmetry. In particular we calculate the amplitude ratio C/sub +//Câ, where C(T) = C/sub +- /chemically bondT-T/sub c/chemically bondâ»Â¹Â² and the coefficients C/sub +/ and Câ are associated with the behavior of C(T) above and below T/sub c/, respectively. We conclude that the value of the amplitude ratio observed experimentally is inconsistent with ordinary s-wave pairing. For an orthorhombic crystal only triplet superconductivity is possible. Assuming tetragonal symmetry we find that either triplet pairing or some d-wave singlet states are allowed. The latter must have an order parameter transforming like d/sub x//sub z/,d/sub y//sub z/. This singlet case lies within ...
Non-Ohmic tunnel junctions are believed to occur in systems where the exciton and orthogonality c... more Non-Ohmic tunnel junctions are believed to occur in systems where the exciton and orthogonality catastrophe effects significantly modify tunneling rates. Here we present a simple non-perturbative treatment of the thermodynamic and transport properties of subOhmic and superOhmic tunnel junctions. The large-N approximation demonstrates the existence of a quantum phase transition in subOhmic but not superOhmic tunnel junctions. In addition, we find a pseudogap which vanishes continuously as the transition is approached.
We present a simplified polymer model for twist-boundary phases in liquid crystals. The thermodyn... more We present a simplified polymer model for twist-boundary phases in liquid crystals. The thermodynamic phases of this model are characterized by an angle 2pialpha~. There are incommensurate phases with alpha~ an irrational number and commensurate phases with alpha~=P/Q, with P and Q relatively prime integers. The latter have quasicrystalline symmetry for Q=5 or Q>6. Equilibrium phases with all values of alpha~ can be produced by varying a control parameter alpha. The curve alpha~(alpha) is an incomplete devil's staircase with finite locking intervals about every rational alpha~.
Based on a mean field analysis of the Chen-Lubensky model we extend an earlier discussion regardi... more Based on a mean field analysis of the Chen-Lubensky model we extend an earlier discussion regarding the effect of chirality on the region of the phase diagram where the Cholesteric, Smectic-A, and Smectic- C* phases meet (i.e., the N* AC* point). We show that, on the Sm-C* side of the phase diagram, a second twist grain boundary (or chiral smectic)
Bogoliubov theory of Coulomb-coupled [m ↑ m ↓ 0] quantum Hall states. Daniel P. Arovas and Scot R... more Bogoliubov theory of Coulomb-coupled [m ↑ m ↓ 0] quantum Hall states. Daniel P. Arovas and Scot R. Renn Department of Physics, University of California at San Diego, La Jolla, California 92093. Received 4 May 1994 The ...
Recently, Inderees et al. have observed inverse-square-root behavior of specific heat of YBaâCuâO... more Recently, Inderees et al. have observed inverse-square-root behavior of specific heat of YBaâCuâOââ/sub delta/ near T/sub c/ corresponding to Gaussian fluctuations. We analyze their results using the most general Landau theories of superconductivity that are consistent with either orthorhombic or tetragonal crystal symmetry. In particular we calculate the amplitude ratio C/sub +//Câ, where C(T) = C/sub +- /chemically bondT-T/sub c/chemically bondâ»Â¹Â² and the coefficients C/sub +/ and Câ are associated with the behavior of C(T) above and below T/sub c/, respectively. We conclude that the value of the amplitude ratio observed experimentally is inconsistent with ordinary s-wave pairing. For an orthorhombic crystal only triplet superconductivity is possible. Assuming tetragonal symmetry we find that either triplet pairing or some d-wave singlet states are allowed. The latter must have an order parameter transforming like d/sub x//sub z/,d/sub y//sub z/. This singlet case lies within ...
Non-Ohmic tunnel junctions are believed to occur in systems where the exciton and orthogonality c... more Non-Ohmic tunnel junctions are believed to occur in systems where the exciton and orthogonality catastrophe effects significantly modify tunneling rates. Here we present a simple non-perturbative treatment of the thermodynamic and transport properties of subOhmic and superOhmic tunnel junctions. The large-N approximation demonstrates the existence of a quantum phase transition in subOhmic but not superOhmic tunnel junctions. In addition, we find a pseudogap which vanishes continuously as the transition is approached.
We present a simplified polymer model for twist-boundary phases in liquid crystals. The thermodyn... more We present a simplified polymer model for twist-boundary phases in liquid crystals. The thermodynamic phases of this model are characterized by an angle 2pialpha~. There are incommensurate phases with alpha~ an irrational number and commensurate phases with alpha~=P/Q, with P and Q relatively prime integers. The latter have quasicrystalline symmetry for Q=5 or Q>6. Equilibrium phases with all values of alpha~ can be produced by varying a control parameter alpha. The curve alpha~(alpha) is an incomplete devil's staircase with finite locking intervals about every rational alpha~.
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