scholarly journals Large Hall angle of vortex motion in high- Tc cuprate superconductors revealed by microwave flux-flow Hall effect

2021 ◽  
Vol 104 (2) ◽  
Author(s):  
R. Ogawa ◽  
F. Nabeshima ◽  
T. Nishizaki ◽  
A. Maeda
Keyword(s):  
Hall Effect ◽  
Cuprate Superconductors ◽  
Vortex Motion ◽  
Flux Flow ◽  
High Tc ◽  
Hall Angle

FAR-INFRARED HALL EFFECT IN NORMAL STATE OF YBCO

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3148-3148 ◽  
Author(s):  
M. GRAYSON ◽  
L. RIGAL ◽  
D. C. SCHMADEL ◽  
H. D. DREW ◽  
P.-J. KUNG
Keyword(s):  
Hall Effect ◽  
Normal State ◽  
Cuprate Superconductors ◽  
Polarized Light ◽  
Far Infrared ◽  
Anomalous Hall Effect ◽  
Transport Models ◽  
Scattering Rate ◽  
Hall Angle ◽  
Infrared Frequencies

Cuprate superconductors in the normal state exhibit the "anomalous Hall effect",1ie., the longitudinal components of the current scattters linearly with T whereas the Hall angle obeys a T2 scattering, where T is temperature. To help resolve this anomaly, we have developed a technique to measure the Hall angle at far-infrared frequencies. Measuring the magnetotransmission spectrum of polarized light through thin film of YBCO, we are able to independently measure both the real and imaginary parts of the complex Hall response. With a spectral range from dc to 250 cm -1, a lineshape analysis of the Hall response reveals that the Hall angle spectrum has a non-Lorentzian from thereby ruling out Drude-like transport models of the Hall effect. Instead it shows a dominant Loretnzian-squared response, implying a square-scattering behavior with a scattering rate that is linear in T and which quantitatively fits the linear scattering rate of the longitudinal current. The experimental results strongly constrain the number of theories that can accurately describe transport in normal state cuprates.

ENERGY BAND OVERLAPPING IN HIGH-Tc SUPERCONDUCTORS

1996 ◽  
Vol 10 (30) ◽  
pp. 1483-1490 ◽  
Author(s):  
M. MORENO ◽  
R. M. MÉNDEZ-MORENO ◽  
M. A. ORTIZ ◽  
S. OROZCO
Keyword(s):  
Weak Coupling ◽  
Cuprate Superconductors ◽  
Weak Coupling Limit ◽  
Band Model ◽  
Coupling Constant ◽  
High Tc Superconductors ◽  
Energy Bands ◽  
Effective Coupling ◽  
High Tc ◽  
Two Band Model

Multi-band superconductors are analyzed and the relevance of overlapping energy bands to the high-T c of these materials is studied. Within the BCS framework, a two band model with generalized Fermi surface topologies is developed. Values of the overlapped occupancy parameters for typical cuprate superconductors are obtained as a function of the ratio R and the effective coupling constant, λ, in the weak-coupling limit. The overlap scale is of the order or lower than the cutoff (Debye) energy. The typical behavior of the isotope effect is obtained. As these superconductors have transition temperatures above the phonon barrier, the results of this approach are important to the generic understanding of the high-T c superconducting mechanism.

scholarly journals EFFECTS OF c-AXIS HOPPING IN THE INTERLAYER TUNNELING MODEL OF HIGH-Tc LAYERED CUPRATES

1999 ◽  
Vol 13 (13) ◽  
pp. 1619-1632
Author(s):  
BIPLAB CHATTOPADHYAY ◽  
A. N. DAS
Keyword(s):  
Experimental Data ◽  
Transition Temperature ◽  
Cuprate Superconductors ◽  
Interlayer Coupling ◽  
Superconducting Gap ◽  
Tunneling Model ◽  
High Tc ◽  
Optimal Doping ◽  
Pair Tunneling ◽  
Layered Cuprates

We consider the interlayer pair-tunneling model for layered cuprates, including an effective single particle hopping along the c-axis. A phenomenological suppression of the c-axis hopping matrix element, by the pseudogap in cuprate superconductors, is incorporated. At optimal doping, quantities characteristic to the superconducting state, such as the transition temperature and the superconducting gap are calculated. Results from our calculations are consistent with the experimental observations with the noteworthy point that, the superconducting gap as a function of temperature shows excellent match to the experimental data. Predictions within the model, regarding T c variation with interlayer coupling, are natural outcomes which could be tested further.

Optical studies on the high Tc cuprate superconductors

1991 ◽  
Vol 43 (3) ◽  
pp. 4075
Author(s):  
Jiro Tanaka ◽  
Masaaki Shimizu ◽  
Koji Kamiya ◽  
Satoru Miyamoto ◽  
Yukio Tanaka
Keyword(s):  
Cuprate Superconductors ◽  
Optical Studies ◽  
High Tc

Direct Determination of the Velocity of Vortices in High-Tc Superconductors by a Non-Equilibrium Method

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3288-3291
Author(s):  
I. Kirschner ◽  
R. Laiho ◽  
A. C. Bódi ◽  
E. Lähderanta ◽  
I. Vajda
Keyword(s):  
Magnetic Field ◽  
Temperature Gradient ◽  
Vortex Motion ◽  
Direct Determination ◽  
Field Investigation ◽  
High Tc Superconductors ◽  
High Tc ◽  
Pinning Centers ◽  
Non Equilibrium

As is shown, thermally assisted vortex motion can come into being in high-T c superconductors due to the applied temperature gradient. Its behavior strongly depends on the local and global microstructure of the samples, moreover on the temperature and magnetic field. Investigation of the density, size and intensity of the pinning centers of specimens leads to the conclusion that the higher homogeneity immediately weakens and the lower one strenghtens the pinning, thus the former promotes and the latter impedes the vortex motion. The non-equilibrium experimental technique together with a.c. susceptibility measurements render possible the direct determination of the velocity of vortices. Depending on the actual microstructural state of samples it has the values between 6 × 10-2 mm/s and 18 × 10-2 mm/s in the case of Y-Ba-Cu-O specimens investigated.

Carrier Scattering Rates Measured by Hall Effect and Magnetoresistance in the High-Tc Oxides

1991 ◽  
pp. 131-136
Author(s):  
N. P. Ong ◽  
T. R. Chien ◽  
T. W. Jing ◽  
T. V. Ramakrishnan ◽  
Z. Z. Wang ◽  
...  
Keyword(s):  
Hall Effect ◽  
High Tc ◽  
Carrier Scattering ◽  
Scattering Rates

NANOSCOPIC PHASE SEPARATION AND THE UNIVERSAL TRANSPORT AND MAGNETIC PROPERTIES OF HIGH Tc SUPERCONDUCTORS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3528-3531
Author(s):  
J. JUNG ◽  
H. YAN ◽  
H. DARHMAOUI ◽  
M. ABDELHADI
Keyword(s):  
Magnetic Properties ◽  
Phase Separation ◽  
Temperature Dependence ◽  
Current Density ◽  
Low Temperatures ◽  
Energy Barrier ◽  
Vortex Motion ◽  
Superfluid Density ◽  
High Tc Superconductors ◽  
High Tc

We have found the correlation between nanoscopic phase separation in the copper-oxygen planes of YBCO and TlBCCO and the transport and magnetic properties of these materials in the a-b planes such as: the temperature dependence of the critical current density Jc( T ), the temperature dependence of the superfluid density ns( T )∝1/λ2( T ) at low temperatures, the temperature dependence of the normalized logarithmic relaxation rate S(T), and the dependence of the effective energy barrier against vortex motion on the current density Ueff( J ). These properties are controlled by the ratio of the amount of an underdoped filamentary phase to that of an optimally doped one.

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