Huber, T. E., Nikolaeva, A., Konopko, L., Graf, M. J.
Whereas bulk bismuth supports very-high mobility, light, Dirac electrons and holes in its interior, its boundaries support a layer of heavy electrons in surface states formed by spin orbit...
Torsional oscillators and the entropy dilemma of putative supersolid He-4 (2008)
Graf, M. J., Balatsky, A. V., Nussinov, Z., Grigorenko, I., Trugman, S. A.
Solid He-4 is viewed as a nearly perfect Debye solid. Yet, recent calorimetry measurements by the PSU group (J. Low Temp. Phys. 138, 853 (2005) and Nature 449, 1025 (2007)) indicate that at low...
19F nuclear spin relaxation and spin diffusion effects in the single ion magnet LiYF4:Ho3+ (2008)
Malkin, B. Z., Vanyunin, M. V., Graf, M. J., Lago, J., Borsa, F., Lascialfari, A., ...
Temperature and magnetic field dependences of the 19F nuclear spin-lattice relaxation in a single crystal of LiYF4 doped with holmium are described by an approach based on a detailed consideration of...
Pauli-limited upper critical field in dirty d-wave superconductors (2008)
Vorontsov, A. B., Vekhter, I., Graf, M. J.
We calculate the Pauli-limited upper critical field and the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) instability for {\it dirty} d-wave superconductors within the quasiclassical theory using the...
Electronic Duality in Strongly Correlated Matter (2008)
Park, T., Graf, M. J., Boulaevskii, L., Sarrao, J. L., Thompson, J. D.
Superconductivity develops from an attractive interaction between itinerant electrons that creates electron pairs which condense into a macroscopic quantum state--the superconducting state. On the...
Muon spin rotation studies of spin dynamics at avoided level crossings in LiY0.998Ho0.002F4 (2007)
Graf, M. J., Lago, J., Lascialfari, A., Amato, A., Baines, C., Giblin, S. R., ...
We have studied the Ho3+ spin dynamics for LiY0.998Ho0.002F4 through the positive muon (mu+) transverse field depolarization rate lambda_TF as a function of temperature and magnetic field. We find...
Ohishi, K., Heffner, R. H., Morris, G. D., Bauer, E. D., Graf, M. J., ...
We have measured the temperature dependence and magnitude of the superfluid density $\rho_{\rm s}(T)$ via the magnetic field penetration depth $\lambda(T)$ in PuCoGa$_5$ (nominal critical temperature...
Nikolaeva, A., Gitsu, D., Konopko, L., Graf, M. J., Huber, T. E.
We report the observation of a dependence of the low temperature resistance of individual single-crystal bismuth nanowires on the Aharonov-Bohm phase of the magnetic flux threading the wire. 55 and...
On the origin of the decrease in the torsional oscillator period of solid He4 (2006)
Nussinov, Z., Balatsky, A. V., Graf, M. J., Trugman, S. A.
A decrease in the rotational period observed in torsional oscillator measurements was recently taken as a possible indication of a supersolid state of helium. We reexamine this interpretation and...
Microscopic evidence for field-induced magnetism in CeCoIn$_5$ (2006)
Urbano, R. R., Curro, N. J., Thompson, J. D., Sarrao, J. L., Vorontsov, A. B., ...
We present NMR data in the normal and superconducting states of CeCoIn$_5$ for fields close to $H_{\rm c2}(0)=11.8$ T in the $ab$ plane. Recent experiments identified a first-order transition from...
Entropy of solid He4: the possible role of a dislocation glass (2006)
Balatsky, A. V., Graf, M. J., Nussinov, Z., Trugman, S. A.
Solid He4 is viewed as a nearly perfect Debye solid. Yet, recent calorimetry indicates that its low-temperature specific heat has both cubic and linear contributions. These features appear in the...
The nuclear spin-lattice relaxation rate in the PuMGa$_5$ materials (2006)
Bang, Yunkyu, Graf, M. J., Curro, N. J., Balatsky, A. V.
We examine the nuclear spin-lattice relaxation rates $1/T_1$ of PuRhGa$_5$ and PuCoGa$_5$, both in the superconducting and normal states, as well as their Knight shifts. Results for both compounds...
Thermal conductivity in the vicinity of the quantum critical endpoint in Sr3Ru2O7 (2006)
Ronning, F., Hill, R. W., Sutherland, M., Hawthorn, D. G., Tanatar, M. A., Paglione, J., ...
Thermal conductivity of Sr3Ru2O7 was measured down to 40 mK and at magnetic fields through the quantum critical endpoint at H_c = 7.85 T. A peak in the electrical resistivity as a function of field...
Probing spin dynamics and quantum relaxation in LiY0.998Ho0.002F4 via 19F NMR (2005)
Graf, M. J., Lascialfari, A., Borsa, F., Tkachuk, A. M., Barbara, B.
We report measurements of 19F nuclear spin-lattice relaxation 1/T1 as a function of temperature and external magnetic field in LiY0.998Ho0.002F4 single crystal, a single-ion magnet exhibiting...
Phase Diagram and Spectroscopy of FFLO states of two-dimensional d-wave superconductors (2005)
Vorontsov, A. B., Sauls, J. A., Graf, M. J.
Experimental evidence suggests that the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state may be realized in the unconventional, heavy-fermion superconductor CeCoIn$_5$. We present a self-consistent...
Strong electron-phonon coupling in delta-phase stabilized Pu (2005)
Graf, M. J., Lookman, T., Wills, J. M., Wallace, D. C., Lashley, J. C.
Heat capacity measurements of the delta-phase stabilized alloy Pu-Al suggest that strong electron-phonon coupling is required to explain the moderate renormalization of the electronic density of...
Specific heat and materials analysis on U1-xThxPt3 for 0 (2005)
Hettinger, J.D., Cooley, J.C., Hackenberg, R.E., Peterson, E.J., Kelly, A.M., Papin, P.A., ...
Inhomogeneous magnetic order in Th doped UPt3 detected by µSR (2005)
Visser, A. De, Graf, M.J., Opeil, C.P., Cooley, J.C., Smith, J.L., Amato, A., ...
Weak magnetism phenomena in heavy-fermion superconductors: selected $\mu$SR studies (2004)
Amato, A., Graf, M. J., De Visser, A., Amitsuka, H., Andreica, D., Schenck, A.
The behavior of the so-called weak moment antiferromagnetic states, observed in the heavy-fermion superconductors UPt$_3$ and URu$_2$Si$_2$, is discussed in view of recent $\mu$SR results obtained as...
Weak magnetism phenomena in heavy-fermion superconductors: selected µSR studies (2004)
Amato, A., Graf, M.J., Visser, A. De, Amitsuka, H., Andreica, D., Schenck, A.
Lattice Dynamics and the High Pressure Equation of State of Au (2003)
Elastic constants and zone-boundary phonon frequencies of gold are calculated by total energy electronic structure methods to twofold compression. A generalized force constant model is used to...
Graf, M. J., Opeil, C. P., Huber, T. E.
We report measurements of the low temperature (T = 0.5 K) oscillatory magnetization in a high-density array of 50 micron diameter wires of polycrystalline Bi utilizing a high sensitivity silicon...
Confinement effects and surface-induced charge carriers in Bi Quantum Wires (2003)
Huber, T. E., Nikolaeva, A., Konopko, L., Gitsu, D., Foss, C. A., ...
We present measurements of Shubnikov-de Haas oscillations in arrays of bismuth nanowires with diameters comparable to the Fermi wavelength. For 80-nm wires the hole concentration is less than 30% of...
Thermoelectric power of Bi and Bi(1-x)Te(x), x=0.0014,in porous Vycor glass (2003)
Huber, T. E., Nikolaeva, A., Gitsu, A., Konopko, D., Graf, M. J., Huang, J.
Semiconductor quantum wires constitute a promising thermoelectric material because of the increase of the electronic density of states in low-dimensional materials. We studied the...
Darling, T. W., Graf, M. J., Proffen, Th., Heffner, R. H., Lee, Yongjae, ...
The temperature and pressure dependence of the thermal displacements and lattice parameters were obtained across the $\gamma \to \alpha$ phase transition of Ce using high-pressure, high-resolution...
Ultrafast quasiparticle relaxation dynamics in normal metals and heavy fermion materials (2003)
Ahn, K. H., Graf, M. J., Trugman, S. A., Demsar, J., Averitt, R. D., Sarrao, J. L., ...
We present a detailed theoretical study of the ultrafast quasiparticle relaxation dynamics observed in normal metals and heavy fermion materials with femtosecond time-resolved optical pump-probe...
Bang, Yunkyu, Graf, M. J., Balatsky, A. V.
We calculated the nuclear spin-lattice relaxation rate $1/T_1$ for the D+iD superconducting state with impurities. We found that small amount of unitary impurities quickly produces the residual...
Onset of antiferromagnetism in UPt_{3} via Th-substitution studied by muon spin spectroscopy (2003)
Graf, M. J., De Visser, A., Opeil, C. P., Cooley, J. C., Smith, J. L., Amato, A., ...
Muon spin spectroscopy has been used to study in detail the onset of large-moment antiferromagnetism (LMAF) in UPt_{3} as induced by Th substitution. Zero-field experiments have been carried out on a...
$1/T_1$ in the D-wave superconducting state with coexisting antiferromagnetism (2003)
Bang, Yunkyu, Graf, M. J., Balatsky, A. V., Thompson, J. D.
We consider a general D-wave superconducting gap function in the presence of coexisting antiferromagnetic (AFM) long-rang order. We find that the D-wave order parameter develops additional nodes...
Quasiparticle relaxation dynamics in heavy fermion compounds (2003)
Demsar, J., Averitt, R. D., Ahn, K. H., Graf, M. J., Trugman, S. A., Kabanov, V. V., ...
We present the first femtosecond studies of electron-phonon (e-ph) thermalization in heavy fermion compounds. The e-ph thermalization time tau_{ep} increases below the Kondo temperature by more than...
Onset of antiferromagnetism in UPt3 via Th substitution: a muon spin spectroscopy study (2003)
Graf, M.J., Visser, A. De, Opeil, C.P., Cooley, J.C., Smith, J.L., Amato, A., ...
Lattice dynamics and correlated atomic motion from the atomic pair distribution function (2002)
Heffner, R. H., Graf, M. J., Billinge, S. J. L.
The mean-square relative displacements (MSRD) of atomic pair motions in crystals are studied as a function of pair distance and temperature using the atomic pair distribution function (PDF). The...
Magnetic quantum critical point and superconductivity in UPt3 doped with Pd (2000)
De Visser, A., Graf, M. J., Estrela, P., Amato, A., Baines, C., Andreica, D., ...
Transverse-field muon spin relaxation measurements have been carried out on the heavy-fermion superconductor UPt3 doped with small amounts of Pd. We find that the critical Pd concentration for the...
Identifying the pairing symmetry in the Sr2RuO4 superconductor (2000)
We have analyzed heat capacity and thermal conductivity measurements of Sr2RuO4 in the normal and superconducting state and come to the conclusion that an order parameter with nodal lines on the...
Interlayer Tunneling of Quasiparticles and Cooper Pairs in Bi-2212 Single Crystal Whiskers (2000)
Latyshev, Yu. I., Pavlenko, V. N., Yamashita, T., Bulaevskii, L. N., Graf, M. J., ...
The interlayer tunneling has been studied on high quality Bi-2212 stacks of micron to the submicron lateral size. We found that low temperature and low voltage tunneling I-V characteristics can be...
Muon localization site in U(Pt,Pd)3 (2000)
Schenck, A., Keizer, R.J., Visser, A. De, Amato, A., Andreica, D., Gygax, F.N., ...
Magnetic quantum critical point and superconductivity in UPt3 doped with Pd (2000)
Visser, A. De, Graf, M.J., Estrela, P., Amato, A., Baines, C., Andreica, D., ...
Electronic Transport in a Three-dimensional Network of 1-D Bismuth Quantum Wires (1999)
The resistance R of a high density network of 6 nm diameter Bi wires in porous Vycor glass is studied in order to observe its expected semiconductor behavior. R increases from 300 K down to 0.3 K....
Muon localization site in U(Pt,Pd)3 (1999)
Schenck, A., Keizer, R. J., De Visser, A., Amato, A., Andreica, D., Gygax, F. N., ...
The angular and temperature (10-250 K) variation of the Knight shift of single-crystalline U(Pt0.95Pd0.05)3 has been measured in transverse field (B=0.6 T) mSR experiments. By analysing the...
Search for a quantum phase transition in U(Pt_(1-x)Pd_x)_3 (1999)
Graf, M. J., Keizer, R. J., De Visser, A., Hannahs, S. T.
Pd in U(Pt_{1-x}Pd_x)_3 suppresses the superconducting T_c to 0 K at critical concentration x_c of 0.007 and induces a conventional AFM state for x > x_c. The resistivity below 1 K shows a deviation...
Local Time-Reversal Symmetry Breaking in d_(x2-y2) Superconductors (1999)
Graf, M. J., Balatsky, A. V., Sauls, J. A.
We show that an isolated impurity in a spin singlet d_{x2-y2} superconductor generates a d_{xy} order parameter with locally broken time-reversal symmetry. The origin of this effect is a coupling...
Transport in the Heavy Fermion Superconductor UPt3 (1999)
We report new theoretical results and analysis for the transport properties of superconducting UPt3 based on the leading models for the pairing symmetry. We use Fermi surface data and the measured...
Bulaevskii, L. N., Graf, M. J., Maley, M. P.
We consider the quasiparticle c-axis conductivity in highly anisotropic layered compounds in the presence of the magnetic field parallel to the layers. We show that at low temperatures the...
Superconductivity in heavy-fermion U(Pt,Pd)3 and its interplay with magnetism (1999)
Keizer, R. J., De Visser, A., Graf, M. J., Menovsky, A. A., Franse, J. J. M.
The effect of Pd doping on the superconducting phase diagram of the unconventional superconductor UPt3 has been measured by (magneto)resistance, specific heat, thermal expansion and magnetostriction....
Studies of superconductivity in U(Pt1-xPdx)3 for x < 0.006 (1999)
Graf, M. J., Keizer, R. J., De Visser, A., Franse, J. J. M.
We report measurements of the specific heat and resistivity (T < 1 K) for high quality polycrystals of U(Pt1-xPdx)3 with x < 0.006. The Tc-x phase diagram can be constructed, and superconductivity is...
Interlayer Transport of Quasiparticles and Cooper pairs in Bi2Sr2CaCu2O8+y Superconductors (1999)
Latyshev, Yu. I., Yamashita, T., Bulaevskii, L. N., Graf, M. J., Balatsky, A. V., Maley, M. P.
We study the c-axis transport of stacked, intrinsic junctions in Bi2Sr2CaCu2O8+y single crystals, fabricated by the double-sided ion beam processing technique from single crystal whiskers....
Suppression of Superconductivity in Single Crystals of UPt_3 by Pd Substitution (1999)
Graf, M. J., Keizer, R. J., De Visser, A., Menovsky, A. A., Franse, J. J. M.
The suppression of superconductivity by substitution effects has been measured in high quality single crystals of U(Pt_{1-x} Pd_x)_3 with 0
Superconductivity in heavy-fermion U(Pt,Pd)3 and its interplay with magnetism (1999)
Keizer, R.J., Visser, A. De, Graf, M.J., Menovsky, A.A., Franse, J.J.M.
Suppression of superconductivity in single crystals of UPt3 by Pd substitution (1999)
Graf, M.J., Keizer, R.J., Visser, A. De, Menovsky, A.A., Franse, J.J.M.
We present theoretical calculations of the thermal conductivity for the accidental degeneracy and enlarged symmetry group models that have been proposed to explain the phase diagram of UPt3. The...
Suppression of Superconductivity in UPt_3 Single Crystals (1998)
Kycia, J. B., Hong, J. I., Graf, M. J., Sauls, J. A., Seidman, D. N., Halperin, W. P.
High quality single crystals of UPt_3 have been prepared by vertical float-zone refining in ultra-high vacuum. We find that the superconducting transition temperature can be varied systematically by...
On the interplay of small-moment magnetism and superconductivity in UPt3 (1998)
Visser, A. De, Keizer, R.J., Graf, M.J., Menovsky, A.A., Franse, J.J.M.
Universality in Transport Processes of Unconventional Superconductors (1996)
We show that some of the low temperature transport coefficients (e.g., electrical and thermal conductivities, viscosity and sound attenuation) are {\it universal}, i.e., independent of the impurity...
Thermal Conductivity of Superconducting UPt$_3$ at Low Temperatures (1995)
We study the thermal conductivity within the E$_{1g}$ and E$_{2u}$ models for superconductivity in UPt$_3$ and compare the theoretical results for electronic heat transport with recently measured...
Graf, M. J., Sauls, J. A., Rainer, D.
We use the quasiclassical theory of superconductivity to calculate the electronic contribution to the thermal conductivity. The theory is formulated for low temperatures when heat transport is...
Electromagnetic Absorption in an Anisotropic Layered Superconductor (1995)
We calculate the infrared conductivity tensor of a layered superconductor considering two different order parameter symmetries: strongly anisotropic $s$-wave with line nodes, and pure ($d_{x^2-y^2}$)...
Infrared Conductivity in Layered $d$-wave Superconductors (1995)
Graf, M. J., Palumbo, Mario, Rainer, D., Sauls, J. A.
We calculate the infrared conductivity of a stack of coupled, two-dimensional superconducting planes within the Fermi liquid theory of superconductivity. We include the effects of random scattering...
Electronic duality in strongly correlated matter
Park, T., Graf, M. J., Boulaevskii, L., Sarrao, J. L., Thompson, J. D.
Superconductivity develops from an attractive interaction between itinerant electrons that creates electron pairs, which condense into a macroscopic quantum state—the superconducting state. On the...