Mishra, V., Vorontsov, A., Hirschfeld, P. J., Vekhter, I.
Within a two-band model for the recently discovered ferropnictide materials, we calculate the thermal conductivity assuming general superconducting states of $A_{1g}$ ("s-wave") symmetry, considering...
Theory of Resistivity Upturns in Metallic Cuprates (2009)
Chen, W., Andersen, Brian M., Hirschfeld, P. J.
We propose that the experimentally observed resistivity upturn of cuprates at low temperatures may be explained by properly accounting for the effects of disorder in a strongly correlated metallic...
Effects of cobalt doping and three-dimensionality in $BaFe_2As_2$ (2009)
Kemper, A. F., Cao, C., Hirschfeld, P. J., Cheng, H-P.
We investigate the dual roles of a cobalt impurity in the Ba-122 ferropnictide superconductor in the state with coexisting collinear spin density wave (SDW) order as a dopant and as a scattering...
Origin of Gap Anisotropy in Spin Fluctuation Models of the Fe-pnictides (2009)
Maier, T. A., Graser, S., Scalapino, D. J., Hirschfeld, P. J.
We discuss the large gap anisotropy found for the A1g (s-wave) state in RPA spin-fluctuation and functional renormalization group calculations and show how the simple arguments leading to isotropic...
Probing the pairing symmetry of the iron pnictides with electronic Raman scattering (2009)
Boyd, G. R., Devereaux, T. P., Hirschfeld, P. J., Mishra, V., Scalapino, D. J.
An important issue in the study of the iron-arsenic based superconductors is the symmetry of the superconducting gap, a problem complicated by multiple gaps on different Fermi surface sheets....
Mishra, V., Boyd, G., Graser, S., Maier, T., Hirschfeld, P. J., Scalapino, D. J.
We show, using a simple model, how ordinary disorder can gap an extended-$s$ ($A_{1g}$) symmetry superconducting state with nodes. The concommitant crossover of thermodynamic properties, particularly...
Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides (2008)
Graser, S., Maier, T. A., Hirschfeld, P. J., Scalapino, D. J.
Weak-coupling approaches to the pairing problem in the iron pnictide superconductors have predicted a wide variety of superconducting ground states. We argue here that this is due both to the...
Magnetic correlations on the full chains of Ortho-II YBa$_2$Cu$_3$O$_{6.5}$ (2008)
We propose that the NMR line shape on the chain Cu in the stoichiometric high-$T_c$ superconductor Ortho-II YBa$_2$Cu$_3$O$_{6.5}$ is determined by the magnetization induced on Cu near O vacancies,...
Extinction of quasiparticle interference in underdoped cuprates with coexisting order (2008)
Andersen, Brian M., Hirschfeld, P. J.
Recent scanning tunnelling spectroscopy measurements [Y. Koksaka et al., Nature 454, 1072 (2008)] have shown that dispersing quasiparticle interference peaks in Fourier transformed conductance maps...
Boyd, G. R., Hirschfeld, P. J., Vekhter, I., Vorontsov, A. B.
Experiments on several novel superconducting compounds have observed oscillations of the specific heat when an applied magnetic field is rotated with respect to the crystal axes. The results are...
Foyevtsova, Kateryna, Valenti, Roser, Hirschfeld, P. J.
On the basis of the three-band Hubbard model for the cuprates, we calculate the magnetic superexchange between Cu ions in the presence of dopants up to fifth-order in perturbation theory. We find...
Slezak, J. A., Lee, Jinho, Wang, M., McElroy, K., Fujita, K., Andersen, B. M., ...
Many theoretical models of high temperature superconductivity focus only on the doping dependence of the CuO2 plane electronic structure. But such models are manifestly insufficient to explain the...
Andersen, Brian M., Graser, S., Hirschfeld, P. J.
Impurity resonances observed by scanning tunneling spectroscopy in the superconducting state have been used to deduce properties of the underlying pure state. Here we study a longstanding puzzle...
Insensitivity of superconductivity to disorder in the cuprates (2008)
Kemper, A. F., Maier, T. A., Jarrell, M., Hirschfeld, P. J., Cheng, H-P.
Using a dynamical cluster quantum Monte Carlo approximation, we investigate the effect of local disorder on the stability of d-wave superconductivity including the effect of electronic correlations...
Sublattice model of atomic scale pairing inhomogeneity in a superconductor (2008)
Mishra, Vivek, Hirschfeld, P. J., Barash, Yu. S.
We study a toy model for a superconductor on a bipartite lattice, where intrinsic pairing inhomogeneity is produced by two different coupling constants on the sublattices. The simplicity of the model...
Graser, S., Boyd, G. R., Cao, Chao, Cheng, Hai-Ping, Hirschfeld, P. J., Scalapino, D. J.
Since the discovery of high-Tc LaO_1-xF_xFeAs, and other such systems based on FeAs layers, several proposals have been made for the superconducting order parameter Delta_k, on both phenomenological...
Cao, Chao, Hirschfeld, P. J., Cheng, Hai-Ping
We report density functional theory calculations for the parent compound LaOFeAs of the newly discovered 26K Fe-based superconductor LaO$_{1-x}$F$_x$FeAs. We find that the ground state is an ordered...
Alldredge, J. W., Lee, Jinho, McElroy, K., Wang, M., Fujita, K., Kohsaka, Y., ...
A complete knowledge of its excitation spectrum could greatly benefit efforts to understand the unusual form of superconductivity occurring in the lightly hole-doped copper-oxides. Here we use...
Local quasiparticle lifetimes in a d-wave superconductor (2007)
Graser, S., Hirschfeld, P. J., Scalapino, D. J.
Scanning tunnelling spectroscopy (STS) measurements find that the surface of Bi-2212 is characterized by nanoscale sized regions, "gap patches," which have different magnitudes for the d-wave energy...
I. Vekhter, P. J. Hirschfeld, J. P. Carbotte, E. J. Nicol
The density of states of a 2D d-wave superconductor in the vortex state with applied magnetic field H in the plane is shown to exhibit fourfold oscillations as a function of the angle of the field...
I. Vekhter, J. P. Carbotte, P. J. Hirschfeld, E. J. Nicol
Quasiparticle properties of d-wave superconductors in the vortex state
Conserving slave boson approximations for the Anderson model beyond NCA (2007)
J. Kroha, P. Wölfle, T. A. Costi, P. J. Hirschfeld, K. A. Muttalib
riodic Anderson models. These are expected to describe heavy fermion systems and possibly high T c superconductors. Thus, the single--impurity Anderson model may serve as a test ground for...
K. Ziegler, Ziegler Hettler, P. J. Hirschfeld
We consider a disordered d--wave superconductor in two dimensions. Recently, we have shown in an exact calculation that for a lattice model with a Lorentzian distributed random chemical potential the...
Breakdown of universal transport in correlated d-wave superconductors (2007)
Andersen, Brian M., Hirschfeld, P. J.
The prediction and observation of low-temperature universal thermal conductivity in cuprates has served as a keystone of theoretical approaches to the superconducting state, but recent measurements...
Defects in correlated metals and superconductors (2007)
Alloul, H., Bobroff, J., Gabay, M., Hirschfeld, P. J.
In materials with strong local Coulomb interactions, simple defects such as atomic substitutions strongly affect both macroscopic and local properties of the system. A nonmagnetic impurity, for...
Structure of BSCCO supermodulation from ab initio calculations (2007)
He, Y., Graser, S., Hirschfeld, P. J.
We present results of density functional theory (DFT) calculation of the structural supermodulation in BSCCO-2212 structure, and show that the supermodulation is indeed a spontaneous symmetry...
Conserving slave boson approximations for the Anderson model beyond NCA. (2007)
Kroha, Johann, Woelfle, Peter, Costi, Theodoulos A., Hirschfeld, P.J., Muttalib, K.A.
Novel Josephson Effects in d-wave Superconductor Junctions with Antiferromagnetic Interlayers (2007)
Andersen, Brian M., Barash, Yu. S., Graser, S., Hirschfeld, P. J.
We calculate the dc supercurrent through a Josephson tunnel junction consisting of an antiferromagnetic (AF) interlayer sandwiched between two d-wave superconductors (d). Such d/AF/d junctions...
Superconducting gap variations induced by structural supermodulation in BSCCO (2007)
Andersen, Brian M., Hirschfeld, P. J., Slezak, James A.
We discuss the possibility that the strain field introduced by the structural supermodulation in Bi-2212 and certain other cuprate materials may modulate the superconducting pairing interaction. We...
Tc suppression and resistivity in cuprates with out of plane defects (2007)
Graser, S., Dahm, T., Hirschfeld, P. J.
Recent experiments introducing controlled disorder into optimally doped cuprate superconductors by both electron irradiation and chemical substitution have found unusual behavior in the rate of...
Disorder-Induced Static Antiferromagnetism in Cuprate Superconductors (2006)
Andersen, Brian M., Hirschfeld, P. J., Kampf, Arno P., Schmid, Markus
Using model calculations of a disordered d-wave superconductor with on-site Hubbard repulsion, we show how dopant disorder can stabilize novel states with antiferromagnetic order. We find that the...
Harter, J. W., Andersen, B. M., Bobroff, J., Gabay, M., Hirschfeld, P. J.
We study a model of a d-wave superconductor with strong potential scatterers in the presence of antiferromagnetic correlations and apply it to experimental nuclear magnetic resonance (NMR) results on...
Andersen, Brian M., Hirschfeld, P. J.
The low-temperature thermal conductivity \kappa_0/T of d-wave superconductors is generally thought to attain a "universal" value independent of disorder at sufficiently low temperatures, providing an...
Signatures of modulated pair interaction in cuprate superconductors (2006)
Nunner, Tamara S., Hirschfeld, P. J., Andersen, Brian M., Melikyan, Ashot, McElroy, K.
Recent low-temperature scanning tunnelling spectroscopy experiments on the surface of BSCCO-2212 have revealed a strong positive correlation between the position of localized resonances at -960 meV...
Thermodynamic transitions in inhomogeneous d-wave superconductors (2006)
Andersen, Brian M., Melikyan, Ashot, Nunner, Tamara S., Hirschfeld, P. J.
We study the spectral and thermodynamic properties of inhomogeneous d-wave superconductors within a model where the inhomogeneity originates from atomic scale pair disorder. This assumption has been...
He, Y., Nunner, T. S., Hirschfeld, P. J.
The cuprate material BSCCO-2212 is believed to be doped by a combination of cation switching and excess oxygen. The interstitial oxygen dopants are of particular interest because scanning tunnelling...
Barash, Yuri, Bobkova, I. V., Andersen, Brian M., Kopp, T., Hirschfeld, P. J.
Spectra and spin structures of Andreev interface states and the Josephson current are investigated theoretically in junctions between clean superconductors (SC) with ordered interlayers. The...
0-pi transitions in Josephson junctions with antiferromagnetic interlayers (2005)
Andersen, Brian M., Bobkova, I. V., Hirschfeld, P. J., Barash, Yu. S.
We show that the dc Josephson current through superconductor-antiferromagnet-superconductor (S/AF/S) junctions manifests a remarkable atomic scale dependence on the interlayer thickness. At low...
Disorder effects on the intrinsic nonlinear current density in YBa$_2$Cu$_3$O$_{7-\delta}$ (2005)
Andersen, Brian M., Booth, James C., Hirschfeld, P. J.
We present harmonic generation measurements of the intrinsic nonlinear current density $j_2$ of YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) films at temperatures close the $T_c$. Experiments on a range of...
24th International Conference on Low Temperature Physics (2005)
Takano, Y, Hershfield, S P, Hill, S O, Hirschfeld, P J, Goldman, A M
Nunner, Tamara S., Chen, Wei, Andersen, Brian M., Melikyan, Ashot, Hirschfeld, P. J.
The local density of states power spectrum of optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (BSCCO) has been interpreted in terms of quasiparticle interference peaks corresponding to an "octet'' of...
Bound states at the interface between antiferromagnets and superconductors (2005)
Andersen, B. M., Bobkova, I. V., Hirschfeld, P. J., Barash, Yu. S.
We present a detailed theoretical investigation of interfaces and junctions involving itinerant antiferromagnets. By solving the Bogoliubov-de Gennes equations with a tight-binding model on a square...
Nodal Quasiparticle Lifetimes in Cuprate Superconductors (2005)
Dahm, T., Hirschfeld, P. J., Scalapino, D. J., Zhu, L.
A new generation of angular-resolved photoemission spectroscopy (ARPES) measurements on the cuprate superconductors offer the promise of enhanced momentum and energy resolution. In particular, the...
Andreev states near short-ranged pairing potential impurities (2005)
Andersen, Brian M., Melikyan, Ashot, Nunner, Tamara S., Hirschfeld, P. J.
We study Andreev states near atomic scale modulations in the pairing potential in both $s$- and d-wave superconductors with short coherence lengths. For a moderate reduction of the local gap, the...
Ab Initio Calculation of Impurity Effects in Copper Oxide Materials (2005)
We describe a method for calculating, within density functional theory, the electronic structure associated with typical defects which substitute for Cu in the CuO2 planes of high-Tc superconducting...
Dopant-modulated pair interaction in cuprate superconductors (2005)
Nunner, Tamara S., Andersen, Brian M., Melikyan, Ashot, Hirschfeld, P. J.
Comparison of recent experimental STM data with single-impurity and many-impurity Bogoliubov-de Gennes calculations strongly suggests that random out-of-plane dopant atoms in cuprates modulate the...
Microwave conductivity of d-wave superconductors with extended impurities (2004)
Nunner, Tamara S., Hirschfeld, P. J.
We investigate the influence of extended scatterers on the finite temperature and finite frequency microwave conductivity of d-wave superconductors. For this purpose we generalize a previous...
Anomaly at Delta_k in the ARPES spectrum of dirty superconductors (2004)
Dahm, T., Hirschfeld, P. J., Zhu, L., Scalapino, D. J.
Elastic forward scattering can lead to an anomaly in the ARPES spectrum of the cuprate superconductors. Here we discuss how this anomaly can be used to provide a measurement of the superconducting...
Relating STM, ARPES, and Transport in the Cuprate Superconducting State (2004)
Scalapino, D. J., Nunner, T. S., Hirschfeld, P. J.
We discuss a wealth of data from various types of experiments which together suggest that the superconducting state of optimally to overdoped BSCCO-2212 can be well-described by the BCS theory with a...
Bobkova, I. V., Hirschfeld, P. J., Barash, Yu. S.
We present a formulation of the quasiclassical theory of junctions between itinerant antiferromagnets (AF) and s-wave (sSC) and d-wave superconductors (dSC). For the simplest two-sublattice...
Elastic forward scattering in the cuprate superconducting state (2004)
Zhu, L., Hirschfeld, P. J., Scalapino, D. J.
We investigate the effect of elastic forward scattering on the ARPES spectrum of the cuprate superconductors. In the normal state, small angle scattering from out-of-plane impurities is thought to...
Half - h/2e - Oscillations of SQUIDs (2004)
Schneider, C. W., Hammerl, G., Logvenov, G., Kopp, T., Kirtley, J. R., Hirschfeld, P. J., ...
The current-voltage characteristics of Superconducting Quantum Interference Devices (SQUIDs) are known to modulate as a function of applied magnetic field with a period of one flux quantum...
Interface-mediated pairing in field effect devices (2004)
Koerting, V., Yuan, Qingshan, Hirschfeld, P. J., Kopp, T., Mannhart, J.
We consider the pairing induced in a strictly 2D electron gas (2DEG) by a proximate insulating film with polarizable localized excitations. Within a model of interacting 2D electrons and localized...
Electronic structure of d-wave superconducting quantum wires (2004)
Bobkov, A. M., Nunner, T. S., Barash, Yu. S., Hirschfeld, P. J.
We present analytical and numerical results for the electronic spectra of wires of a d-wave superconductor on a square lattice. The spectra of Andreev and other quasiparticle states, as well as the...
Tsai, Shan-Wen, Hirschfeld, P. J.
A d-wave superconductor with isolated strong non-magnetic impurities should exhibit an upturn in the penetration depth at low temperatures. Here we calculate how an external magnetic field supresses...
Power spectrum of many impurities in a d-wave superconductor (2003)
Zhu, Lingyin, Atkinson, W. A., Hirschfeld, P. J.
Recently the structure of the measured local density of states power spectrum of a small area of the \BSCCO (BSCCO) surface has been interpreted in terms of peaks at an "octet" of scattering wave...
Relaxation of Hot Quasiparticles in a d-Wave Superconductor (2003)
Howell, P. C., Rosch, A., Hirschfeld, P. J.
Motivated by recent pump-probe experiments we consider the processes by which "hot" quasiparticles produced near the antinodes of a d-wave superconductor can relax. We show that in a large region of...
Quantum interference in nested d-wave superconductors: a real-space perspective (2003)
Atkinson, W. A., Hirschfeld, P. J., Zhu, Lingyin
We study the local density of states around potential scatterers in d-wave superconductors, and show that quantum interference between impurity states is not negligible for experimentally relevant...
Two impurities in a d-wave superconductor:local density of states (2002)
Zhu, Lingyin, Atkinson, W. A., Hirschfeld, P. J.
We study the problem of two local potential scatterers in a d-wave superconductor, and show how quasiparticle bound state wave functions interfere. Each single-impurity electron and hole resonance...
Singular current response from isolated impurities in d-wave superconductors (2002)
Tsai, Shan-Wen, Hirschfeld, P. J.
The current response of a d-wave superconductor containing a single impurity is calculated and shown to be singular in the low-temperature limit, leading in the case of strong scattering to a 1/T...
Optical and Thermal-Transport Properties of an Inhomogeneous d-Wave Superconductor (2001)
Atkinson, W. A., Hirschfeld, P. J.
We calculate transport properties of disordered 2D d-wave superconductors from solutions of the Bogoliubov-de Gennes equations, and show that weak localization effects give rise to a finite frequency...
Hirschfeld, P. J., Atkinson, W. A.
We review work on the problem of disorder in the 2D d-wave superconducting state, and show that the symmetries of the normal state and the disorder distribution are vital for understanding the...
Quasi-particle Lifetimes in a d_{x^2-y^2} Superconductor (2001)
Duffy, Daniel, Hirschfeld, P. J., Scalapino, Douglas J.
We consider the lifetime of quasi-particles in a d-wave superconductor due to scattering from antiferromagnetic spin-fluctuations, and explicitly separate the contribution from Umklapp processes...
Nesting symmetries and diffusion in disordered d-wave superconductors (2001)
Yashenkin, A. G., Atkinson, W. A., Gornyi, I. V., Hirschfeld, P. J., Khveshchenko, D. V.
The low-energy density of states (DOS) of disordered 2D d-wave superconductors is extremely sensitive to details of both the disorder model and the electronic band structure. Using diagrammatic...
Comment on ``Density of States of Disordered Two-Dimensional Crystals with Half-Filled Band'' (2001)
Gruzberg, Ilya A., Hirschfeld, P. J., Shytov, A. V.
In a recent letter (PRL 84, 3930 (2000)) Nakhmedov et al. claimed that the Van Hove singularity at $\epsilon=0$ in the density of states (DoS) of the two-dimensional crystal with half-filled...
Nesting Symmetries and Diffusion in Disordered d-Wave Superconductors (2001)
Atkinson, W. A., Gornyi, I. V., Hirschfeld, P. J., Khveshchenko, D. V., Yashenkin, A. G.
Order-parameter holes and theory of microwave conductivity in YBa§2Cu§3O§7§-§#d. (2001)
Hettler, M.H., Hirschfeld, P.J.
Physical Review B, 61(2000) S.11313-16
Nesting symmetries and diffusion in disordered d wave superconductors. (2001)
Yashenkin, A.G., Atkinson, W.A., Gornyi, I.V., Hirschfeld, P.J., Khveshchenko, D.V.
Physical Review Letters, 86(2001) S.5982-85
Thermodynamics of d-wave superconductors in a magnetic field (2000)
Vekhter, I., Hirschfeld, P. J., Nicol, E. J.
We investigate the thermodynamic properties of a two-dimensional d-wave superconductor in the vortex state using a semiclassical approach, and argue that such an approach is valid for the analysis of...
Density of states "width parity" effect in d-wave superconducting quantum wires (2000)
Ziegler, K., Atkinson, W. A., Hirschfeld, P. J.
We calculate the density of states (DOS) in a clean mesoscopic d-wave superconducting quantum wire, i.e. a sample of infinite length but finite width $N$. For open boundary conditions, the DOS at...
Observability of quantum phase fluctuations in cuprate superconductors (2000)
Kwon, Hyok-Jon, Dorsey, Alan T., Hirschfeld, P. J.
We study the order parameter phase fluctuation effects in cuprate superconductors near T=0, using a quasi-two-dimensional d-wave BCS model. An effective phason theory is obtained which is used to...
Details of disorder matter in 2D d-wave superconductors (2000)
Atkinson, W. A., Hirschfeld, P. J., MacDonald, A. H., Ziegler, K.
We demonstrate that discrepancies between predicted low-energy quasiparticle properties in disordered 2D d-wave superconductors occur because of the unanticipated importance of disorder model details...
Vortex in a d-wave superconductor at low temperatures (2000)
Li, Mei-Rong, Hirschfeld, P. J., Woelfle, P.
A systematic perturbation theory is developed to describe the magnetic field-induced subdominant $s$- and $d_{xy}$-wave order parameters in the mixed state of a $d_{x^2-y^2}$-wave superconductor,...
Inhomogeneous order-parameter suppression in disordered d-wave superconductors (2000)
Atkinson, W. A., Hirschfeld, P. J., MacDonald, A. H.
We report on a numerical study of disorder effects in 2D d-wave BCS superconductors. We compare exact numerical solutions of the Bogoliubov-deGennes (BdG) equations for the density of states...
Angle-dependent magnetothermal conductivity in d-wave superconductors (1999)
Vekhter, I., Hirschfeld, P. J.
We analyse the behavior of the thermal conductivity, $\kappa(H)$, in the vortex state of a quasi-two-dimensional d-wave superconductor when both the heat current and the applied magnetic field are in...
Atkinson, W. A., Hirschfeld, P. J., MacDonald, A. H.
The single-impurity problem in d-wave superconductors with asymmetric bands is discussed. The effect of local order parameter suppression near the impurity is to shift the quasiparticle resonance....
Free Energy and Magnetic Penetration Depth of a $d$-Wave Superconductor in the Meissner State (1999)
Li, Mei-Rong, Hirschfeld, P. J., Woelfle, P.
We investigate the free energy and the penetration depth of a quasi-two-dimensional d-wave superconductor in the presence of a weak magnetic field by taking account of thermal, nonlocal and nonlinear...
Li, Mei-Rong, Hirschfeld, P. J., Woelfle, P.
We reply to a recent comment by Bhattacharya et. al. (cond-mat/9812290) on our previous Letter (PRL 81, 5640 (1998)).
Vekhter, I., Hirschfeld, P. J., Carbotte, J. P., Nicol, E. J.
The density of states of a 2D d-wave superconductor in the vortex state with applied magnetic field $\bf H$ in the plane is shown to exhibit fourfold oscillations as a function of the angle of the...
Anisotropic thermodynamics of d-wave superconductors in the vortex state (1998)
Vekhter, I., Hirschfeld, P. J., Carbotte, J. P., Nicol, E. J.
We show that the density of states and the thermodynamic properties of a 2D d-wave superconductor in the vortex state with applied magnetic field $\bf H$ in the plane depend on the angle between $\bf...
Scattering by impurity-induced order parameter ``holes'' in d-wave superconductors (1998)
Hettler, Matthias H., Hirschfeld, P. J.
Nonmagnetic impurities in d-wave superconductors cause strong local suppressions of the order parameter. We investigate the observable effects of the scatterigng off such suppressions in bulk samples...
Quasiparticle Transport in the Vortex State of Unconventional Superconductors (1998)
I consider the problem of the vortex contribution to quasiparticle transport in unconventional superconductors with line nodes, a nd argue that the magnetic field dependence of transport coefficients...
Is the nonlinear Meissner effect unobservable? (1998)
Hirschfeld, P. J., Woelfle, P.
We examine the effects of nonlocal electrodynamics for a d-wave superconductor on the field dependence of the magnetic penetration depth. The linear field dependence predicted in the local limit,...
We comment on a recent letter by Schopohl and Dolgov (SD) which raised the possibility that a d-wave superconductor might be thermodynamically unstable in the limit $T\to 0$. The point of our comment...
We consider, within BCS weak coupling theory, the instability of a $d_{x^2-y^2}$-wave superconductor to a state of mixed symmetry $d+iq$, $q=d_{xy},s$. In zero magnetic field we show that there is a...
Effects of Fermi Surface Anisotropy on Unconventional Superconductivity in UPt_3 (1998)
Haran, G., Hirschfeld, P. J., Sigrist, M.
We discuss the weak-coupling BCS theory of the heavy fermion superconductor UPt_3, accounting for that system's anisotropic, multisheeted Fermi surface by expanding the order parameter and pair...
Quasiparticles in the Vortex State of Dirty d-Wave Superconductors (1998)
Kuebert, C., Hirschfeld, P. J.
We consider the problem of the vortex contribution to thermal properties of dirty d-wave superconductors. In the clean limit, Volovik has argued that the main contribution to the density of states in...
Transport Properties of d-Wave Superconductors in the Vortex State (1998)
Kuebert, C., Hirschfeld, P. J.
We calculate the magnetic field dependence of quasiparticle transport properties in the vortex state of a d-wave superconductor arising solely from the quasiparticle's Doppler shift in the superflow...
Vortex Contribution to Specific Heat of Dirty $d$-Wave Superconductors: Breakdown of Scaling (1997)
Kuebert, C., Hirschfeld, P. J.
We consider the problem of the vortex contribution to thermal properties of dirty d-wave superconductors. In the clean limit, the main contribution to the density of states in a d-wave superconductor...
Ziegler, K., Hettler, M. H., Hirschfeld, P. J.
We consider a disordered d--wave superconductor in two dimensions. Recently, we have shown in an exact calculation that for a lattice model with a Lorentzian distributed random chemical potential the...
Ziegler, K., Hettler, M. H., Hirschfeld, P. J.
In a recent Comment (cond-mat/9701197) on our Letter (PRL 77, 3013 (1996), cond-mat/9604176) Nersesyan and Tsvelik questioned the relevance of our exact calculation of the density of states (DOS) of...
Theory of Thermal Conductivity in YBa_2Cu_3O_{7-\delta} (1996)
Hirschfeld, P. J., Putikka, W. O.
We calculate the electronic thermal conductivity in a d-wave superconductor, including both the effect of impurity scattering and inelastic scattering by antiferromagnetic spin fluctuations. We...
Hirschfeld, P. J., Quinlan, S. M., Scalapino, D. J.
Results of a calculation of the c-axis infrared conductivity sigma_c for a d_{x^2-y^2}-wave superconductor which include both elastic impurity and inelastic spin-fluctuation scattering are presented...
Conserving slave boson approximations for the Anderson model beyond NCA. (1996)
Kroha, Johann, Woelfle, Peter, Costi, Theodoulos A., Hirschfeld, P.J., Muttalib, K.A.
Quinlan, S. M., Hirschfeld, P. J., Scalapino, D. J.
Calculations are presented of the in-plane far-infrared conductivity of a d_{x^2-y^2}-wave superconductor, incorporating elastic scattering due to impurities and inelastic scattering due to spin...
Heat Transport and the Nature of the Order Parameter in Superconducting $UPt_3$ (1995)
Norman, M. R., Hirschfeld, P. J.
Recent thermal conductivity data on the heavy fermion superconductor $UPt_3$ have been interpreted as offering support for an $E_{2u}$ model of the order parameter as opposed to an $E_{1g}$ model. In...
Transport Properties of "Extended-s" State Superconductors (1995)
Borkowski, L. S., Hirschfeld, P. J., Putikka, W. O.
Superconducting states with "extended s-wave" symmetry have been suggested in connection with recent ARPES experiments on BSCCO. In the presence of impurities, thermodynamic properties of such states...
Thermal Conductivity Anisotropy in Superconducting $UPt_3$ (1994)
Fledderjohann, A., Hirschfeld, P. J.
Recent thermal conductivity measurements on $UPt_3$ single crystals by Lussier et al. indicate the existence of a strong b--c anisotropy in the superconducting state. We calculate the thermal...
Multichannel Kondo impurities in superconductors (1994)
Borkowski, L. S., Hirschfeld, P. J.
We discuss the effect of multichannel Kondo impurities on superconductivity. In the strong coupling regime such impurities are pairbreakers, in contrast to the ordinary Kondo effect. Measurements of...
d-Wave Model for Microwave Response of High-Tc Superconductors (1994)
Hirschfeld, P. J., Putikka, W. O., Scalapino, D. J.
We develop a simple theory of the electromagnetic response of a d- wave superconductor in the presence of potential scatterers of arbitrary s-wave scattering strength and inelastic scattering by...
On Distinguishing d-wave from Highly Anisotropic s-wave Superconductors (1994)
Borkowski, L. S., Hirschfeld, P. J.
Systematic impurity doping in the Cu-O plane of the hole-doped cuprate superconductors may allow one to decide between unconvention al ("d-wave") and anisotropic conventional ("s-wave") states as...
Low Temperature Properties of Anisotropic Superconductors with Kondo Impurities (1994)
Borkowski, L. S., Hirschfeld, P. J.
We present a self-consistent theory of superconductors in the presence of Kondo impurities, using large-$N$ slave-boson methods to treat the impurity dynamics. The technique is tested on the s-wave...
Slezak, J. A., Lee, Jinho, Wang, M., McElroy, K., Fujita, K., Andersen, B. M., ...
Many theoretical models of high-temperature superconductivity focus only on the doping dependence of the CuO2-plane electronic structure. However, such models are manifestly insufficient to explain...