Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 36 for “"Pseudogap"”.
-
Investigating the relationship between the superconducting and pseudogap states of the high-temperature superconductor Bi-2201 using scanning tunneling microscopy
… the relationship between the superconducting and pseudogap states of high-temperature superconductors. Although there exist a large number of theories regarding their relationship, the theories fall into one of two broad classes. The first class views the superconducting state as intrinsically …
-
Temperature dependence of impurity resonances in cuprate superconductors
… superconductors (HTS) an additional gap, the pseudogap, develops well above the superconducting transition temperature Tc. The identity of this pseudogap and its relationship to high temperature superconductivity is one of the most interesting outstanding problems in condensed matter physics …
-
Topics in the Theory of High-Temperature Superconductors
… underdoped cuprate superconductors exhibit a pseudogap in the excitation spectrum above the superconducting transition temperature. It is likely that an understanding of the relationship between antiferromagnetism and superconductivity as well as an understanding of the nature of the pseudogap …
-
Phenomenological phase-fluctuation model for the underdoped cuprates
… phenomenological phase-fluctuation model for the pseudogap regime of the underdoped cuprates was discussed. The key idea of the phase-fluctuation scenario in the high-T_c superconductors is the notion that the pseudogap observed in a wide variety of experiments arises from phase fluctuations of …
-
Semiclassical approaches to Quantal Andreev Billiards and Other Topics in Inhomogeneous Superconductivity
… impurity in a cuprate superconductor in the pseudogap regime. It is shown that if the d-wave correlations persist into the pseudogap regime, but with pair-potential phase-fluctuations that destroy long-range ordering, then the low-energy states near extended impurities in the superconducting …
-
Discovery of a Pseudogap Attributed to Charge Density Wave Order at the β-β′ Phase Transition in As2Te3 and the Influence of Cu and Ge Doping on its Properties
… reflectivity we identify the formation of a pseudogap concomitant to the β-As2Te3 to β'-As2Te3 transition. Based on this observation, in addition to a fourfold modulation of the b-axis as reported in the literature, as well as a resistivity anomaly and corresponding hysteresis associated with …
-
Variable Temperature Scanning Tunneling Microscopy Study of a High Temperature Superconductor Bi2Sr2CaCu2O8+d
… of local electronic ordering below the pseudogap energy scale and our failure to observe any tell-tale signs of local superconductivity at Ni impurity sites in the pseudogap regime of a high-TC superconductor. The observation of electronic ordering in the pseudogap regime is a novel and …
-
Exploring strongly interacting gapless states : cuprates, pair density waves, and fluctuating superconductivity
… an effective theory of the strongly interacting pseudogap phase in cuprate high temperature superconductors. In Chapter 2, we study how Fulde-Ferrell state, the simplest form of PDW, responds to incident light. The collective motion of the condensate plays a key role; gauge invariance guides us …
-
Phase Stability In Cobalt-Based L12 Quaternary Intermetallics From Density Functional Theory
… of alloying additions on the position of the pseudogap and number of states at the Fermi level. Charge density differences across the supercell were visualized to analyze changes in bonding behavior. The results indicate that substitutions of Ti, Ta, and Hf in place of the central W atom …
-
Superfluid Density Measurements of High-Temperature Superconducting Films
… (Bi-2212) films. Two competing models of the pseudogap are compared to the temperature dependence of the superfluid density as a function of doping in Bi-2212. Near zero temperature, a maximum in the superfluid density as a function of hole doping is observed at approximately 0.19 holes per …
-
X-Ray scattering investigations of subtle ordering in correlated materials
… the Hidden Order (HO) phase of URu2Si2 and the pseudogap of high Tc cuprates. In the case of URu2 Si2 , the HO phase causes a significant restructuring of the Fermi surface. Thermal conductivity and ultrasound measurements suggest that the lattice degrees of freedom couple strongly to this …
-
Imaging the two gaps of the high temperature superconductor Pb-Bi₂Sr₂CuO₆₊x
… are the center of much debate. The pseudogap state, observed above the superconducting transition temperature Tc, is seen by some as a precursor to the superconducting state. Others view it as a competing phase. Recently, this discussion has focused on the number of energy gaps in …
-
Inelastic X-ray scattering studies of broken symmetry in BSCCO
… materials in the 'strange metal' state above the pseudogap, but are enhanced, particularly around the period four intercell ordering wavevector, as the system is cooled into the pseudogap state. In-plane acoustic phonons are a probe of the electron physics localized on the Cu-O plane due to the …
-
Première investigation du diagramme de phase du composé organique [kappa]-[BEDT-TTF][indice inférieur 2]Cu[N(CN)[indice inférieur 2]]Cl avec la technique de mesure ultrasonore
… éclairci la zone d'ombre concernant l'origine du pseudogap de spin dans ce composé. Celui-ci semble directement relié au point critique qui termine la transition de Mott et ce qui concorde avec les dernières prédictions théoriques. Nous avons observé un second régime de pseudogap qui, lui, n'était …
-
Fabrication and Electronic Transport Properties of Underdoped High Temperature Superconductor Nanowires
… mysteries surrounding the superconducting and pseudogap states in the high-Tc cuprates, we have measured the electronic transport properties of underdoped, high-Tc nanowires and nanostructures. The sizes of the samples involved allow for the investigation of the electronic structure on a …
-
Fabrication and Electronic Transport properties of Underdoped High Temperature Superconductor Nanowires
… mysteries surrounding the superconducting and pseudogap states in the high-Tc cuprates, we have measured the electronic transport properties of underdoped, high-Tc nanowires and nanostructures. The sizes of the samples involved allow for the investigation of the electronic structure on a …
-
Field Theory of Mottness
… T2 contribution to the thermal conductivity, (3) pseudogap, (4) bifurcation of the electron spectrum below the chemical potential, as recently seen in angle-resolved photoemission, (5) insulating behavior away from half-filling, (6) high- and low-energy kinks in the electron dispersion, and (7) …
-
Anistropic phenomena in strongly correlated electron systems
… in the cuprates are reproduced by the theory; a pseudogap destroys the Fermi surface in some places, leaving behind Fermi arcs that closed into hole pockets by lines with very small quasiparticle residue.
-
Unconventional Fermi surface in insulating SmB6 and superconducting YBa2Cu3O6+x probed by high magnetic fields
… of electronic ground state in the enigmatic pseudogap regime, where the antinodal density of states are suppressed below a characteristic temperature $T^*$ above $T_{\rm c}$, has been a subject of active debates. While the quantum oscillations observed in underdoped YBCO$_{6+x}$ have been …
-
Electronic properties of doped Mott insulators and high temperature superconductors
… exists, which can be a candidate for an eventual pseudogap phase in electron doped materials.
Page 1 of 2