scholarly journals Magnetic response of interacting electrons in a spatially non-uniform disordered multi-channel system: exact and mean-field results

2021 ◽  
Vol 137 (1) ◽  
Author(s):  
Arpita Koley ◽  
Santanu K. Maiti
Keyword(s):  
Mean Field ◽  
Magnetic Response ◽  
Channel System ◽  
Interacting Electrons

ULTRASONIC ATTENUATION IN d-WAVE SUPERCONDUCTORS

2001 ◽  
Vol 15 (09n10) ◽  
pp. 269-276 ◽  
Author(s):  
TRIBIKRAM GUPTA ◽  
D. M. GAITONDE
Keyword(s):  
Dopant Concentration ◽  
Ultrasonic Attenuation ◽  
Mean Field Theory ◽  
Mean Field ◽  
Square Lattice ◽  
Clean Limit ◽  
Sign Change ◽  
Attenuation Rate ◽  
Interacting Electrons ◽  
D Wave

We consider a BCS-like model of interacting electrons on a square lattice. Within mean field theory, our model has an instability towards the formation of a d-wave superconducting state. We calculate the longitudinal ultrasonic attenuation rate in the superconducting phase in the clean limit for parameters appropriate to the cuprates. We find that the temperature dependence of the attenuation rate is similar to that observed in conventional superconductors for phonon wavevectors along the direction of the anti-nodes of the gap. However, the attenuation rate for phonon wavevectors along the nodal direction is found to be strikingly different in its temperature and doping dependence. The attenuation rate α S (T) increases in magnitude and shows a sign change in its curvature (when plotted as a function of temperature) with increasing value of dopant concentration.

SPONTANEOUS SYMMETRY BREAKING IN A MICROTUBULE-LIKE SYSTEM

2010 ◽  
Vol 21 (06) ◽  
pp. 825-837 ◽  
Author(s):  
MINGZHE LIU ◽  
RUILI WANG ◽  
RUI JIANG
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Nearest Neighbor ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Low Density ◽  
Channel System ◽  
Multiple Channel ◽  
Proposed Model

This paper studies asymmetric exclusion processes on a microtubule-like system with two species of particles. The model is motivated by the structure of microtubules and kinesins and dyneins moving along microtubules in opposite directions. The proposed model is similar to that in J. Phys. A40, 2275 (2007) in which two-channel TASEPs with narrow entrances and parallel update are studied. This paper extended the above-mentioned work to a multiple-channel hollow cylinder case. Thus, each channel has two nearest neighbors in our model. The corresponding rule for narrow entrances is that particles cannot enter the system if either of two nearest-neighbor sites on neighboring channels is occupied by the other species of particles. The phase diagram of the model is obtained from a mean-field approximation and verified by computer simulations. It is shown that the spontaneous symmetry breaking exists with two asymmetric phases: high/low density and low/low density. The flipping process of particles is observed. Bulk density and particle currents are computed. Monte Carlo simulation results deviate from the mean-field prediction when entrance rate α is high, which is due to neglecting correlations among particles in mean-field calculations. The results are also compared with that obtained from two-channel system with one neighbor narrow entrance in parallel update.

scholarly journals Mean-field phase diagram of interacting electrons

2005 ◽  
Vol 359-361 ◽  
pp. 672-674 ◽  
Author(s):  
Marcin Raczkowski ◽  
Andrzej M. Oleś ◽  
Raymond Frésard
Keyword(s):  
Phase Diagram ◽  
Mean Field ◽  
Field Phase ◽  
Interacting Electrons
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