scholarly journals The effect of lattice-qcd-based gluon propagator on coherence length of quark Cooper pairs in two-flavor color superconductor

2007 ◽  
Vol 11 (4) ◽  
pp. 390-395 ◽  
Author(s):  
Hiyoshi Kiuchi
Keyword(s):  
Lattice Qcd ◽  
Coherence Length ◽  
Gluon Propagator ◽  
Cooper Pairs ◽  
Color Superconductor

scholarly journals Superconducting coherence length of hole-doped cuprates obtained from electron–boson spectral density function

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jungseek Hwang
Keyword(s):  
Spectral Density ◽  
Coherence Length ◽  
Cooper Pair ◽  
Average Frequency ◽  
Spin Fluctuations ◽  
Fermi Velocity ◽  
Cooper Pairs ◽  
Spectroscopic Techniques ◽  
Microscopic Mechanism ◽  
Superconducting Coherence Length

AbstractElectron–boson spectral density functions (EBSDFs) can be obtained from measured spectra using various spectroscopic techniques, including optical spectroscopy. EBSDFs, known as glue functions, are suggested to have a magnetic origin. Here, we investigated EBSDFs obtained from the measured optical spectra of hole-doped cuprates with wide doping levels, from underdoped to overdoped cuprates. The average frequency of an EBSDF provides the timescale for the spin fluctuations to form Cooper pairs. This timescale is directly associated with retarded interactions between electrons. Using this timescale and Fermi velocity, a reasonable superconducting coherence length, which reflects the size of the Cooper pair, can be extracted. The obtained coherence lengths were consistent with those measured via other experimental techniques. Therefore, the formation of Cooper pairs in cuprates can be explained by spin fluctuations, the timescales of which appear in EBSDFs. Consequently, EBSDFs provide crucial information on the timescale of the microscopic mechanism of Cooper pair formation.

scholarly journals LATTICE QCD GLUON PROPAGATORS NEAR TRANSITION TEMPERATURE

2012 ◽  
Vol 27 (09) ◽  
pp. 1250050 ◽  
Author(s):  
V. G. BORNYAKOV ◽  
V. K. MITRJUSHKIN
Keyword(s):  
Transition Temperature ◽  
Lattice Qcd ◽  
Finite Volume ◽  
Momentum Space ◽  
Transition Point ◽  
Gluon Propagator ◽  
Landau Gauge ◽  
Volume Dependence ◽  
Gauge Fixing ◽  
Two Phases

Landau gauge gluon propagators are studied numerically in the SU (3) gluodynamics as well as in the full QCD with the number of flavors nF = 2 using efficient gauge fixing technique. We compare these propagators at temperatures very close to the transition point in two phases: confinement and deconfinement. The electric mass mE has been determined from the momentum space longitudinal gluon propagator. Gribov copy effects are found to be rather strong in the gluodynamics, while in the full QCD case they are weak ("Gribov noise"). Also we analyze finite volume dependence of the transverse and longitudinal propagators.

scholarly journals ABELIAN PROJECTION AND STUDIES OF GAUGE-VARIANT QUANTITIES IN THE LATTICE QCD WITHOUT GAUGE FIXING

1996 ◽  
Vol 11 (13) ◽  
pp. 1081-1093 ◽  
Author(s):  
SERGEI V. SHABANOV
Keyword(s):  
Lattice Qcd ◽  
Continuum Limit ◽  
Gluon Propagator ◽  
Lorentz Invariance ◽  
Gauge Condition ◽  
Gauge Fields ◽  
Gauge Invariant ◽  
Dynamical Reduction ◽  
Gauge Fixing ◽  
The Continuum

We suggest a new (dynamical) Abelian projection of the lattice QCD. It contains no gauge condition imposed on gauge fields so that Gribov copying is avoided. Configurations of gauge fields that turn into monopoles in the Abelian projection can be classified in a gauge-invariant way. In the continuum limit, the theory respects the Lorentz invariance. A similar dynamical reduction of the gauge symmetry is proposed for studies of gauge-variant correlators (like a gluon propagator) in the lattice QCD. Though the procedure is harder for numerical simulations, it is free of gauge-fixing artifacts, like the Gribov horizon and copies.

scholarly journals Superconducting Coherence Length of Hole-doped Cuprates Obtained From Electron-boson Spectral Density Function

2021 ◽  
Author(s):  
Jungseek Hwang
Keyword(s):  
Spectral Density ◽  
Coherence Length ◽  
Cooper Pair ◽  
Average Frequency ◽  
Spin Fluctuations ◽  
Fermi Velocity ◽  
Cooper Pairs ◽  
Spectroscopic Techniques ◽  
Microscopic Mechanism ◽  
Superconducting Coherence Length

Abstract Electron{boson spectral density functions (EBSDFs) can be obtained from measured spectra using various spectroscopic techniques, including optical spectroscopy. EBSDFs, known as glue functions, have a magnetic origin. Here, we investigated EBSDFs obtained from the measured optical spectra of hole-doped cuprates with wide doping levels, from underdoped to overdoped cuprates. The average frequency of an EBSDF provides the timescale for the spin fluctuations to form Cooper pairs. This timescale is directly associated with retarded interactions betweenelectrons. Using this timescale and Fermi velocity, a reasonable superconducting coherence length, which reflects the size of the Cooper pair, can be extracted. The obtained coherence lengths were consistent with those measured via other experimental techniques. Therefore, the formation of Cooper pairs in cuprates can be explained by spin fluctuations, the timescales of which appear in EBSDFs. Consequently, EBSDFs provide crucial information on the timescale of the microscopic mechanism of Cooper pair formation.

scholarly journals A STUDY OF GLUON PROPAGATOR ON COARSE LATTICE

2000 ◽  
Vol 15 (04) ◽  
pp. 229-244 ◽  
Author(s):  
J. P. MA
Keyword(s):  
Lattice Qcd ◽  
Smooth Function ◽  
Qualitative Agreement ◽  
Lattice Spacing ◽  
Continuum Limit ◽  
Gluon Propagator ◽  
Landau Gauge ◽  
Lattice Action ◽  
Lattice Volume ◽  
The Continuum

We study gluon propagator in Landau gauge with lattice QCD, where we use an improved lattice action. The calculation of gluon propagator is performed on lattices with the lattice spacing from 0.40 fm to 0.24 fm and with the lattice volume from (2.40 fm )4 to (4.0 fm )4. We find that the rotation invariance is approximately restored in the q2-range, indicated by the fact that the propagator is a smooth function of the continuum momentum q2. We try to fit our results by two different ways, in the first one we interpret the calculated gluon propagators as a function of the continuum momentum, while in the second we interpret the propagators as a function of the lattice momentum. In both cases we use models which are the same in continuum limit. A qualitative agreement between two fittings is found.

scholarly journals Two-point functions of quenched lattice QCD in Numerical Stochastic Perturbation Theory. (II) The gluon propagator in Landau gauge

2011 ◽  
Vol 842 (1) ◽  
pp. 122-139 ◽  
Author(s):  
F. Di Renzo ◽  
E.-M. Ilgenfritz ◽  
H. Perlt ◽  
A. Schiller ◽  
C. Torrero
Keyword(s):  
Perturbation Theory ◽  
Lattice Qcd ◽  
Gluon Propagator ◽  
Stochastic Perturbation ◽  
Landau Gauge
Sign in / Sign up

Export Citation Format

Share Document