Physics – Condensed Matter – Superconductivity
Scientific paper
2000-06-08
Physics
Condensed Matter
Superconductivity
11 pages, 5 figures, revised version
Scientific paper
10.1103/PhysRevLett.87.227001
In conventional superconductors, the pairing energy gap (\Delta) and superconducting phase coherence go hand-in-hand. As the temperature is lowered, both the energy gap and phase coherence appear at the transition temperature T_c. In contrast, in underdoped high-T_c superconductors (HTSCs), a pseudogap appears at a much higher temperature T^*, smoothly evolving into the superconducting gap at T_c. Phase coherence on the other hand is only established at T_c, signaled by the appearance of a sharp quasiparticle (QP) peak in the excitation spectrum. Another important difference between the two types of superconductors is in the ratio of 2\Delta / T_c=R. In BCS theory, R~3.5, is constant. In the HTSCs this ratio varies widely, continuing to increase in the underdoped region, where the gap increases while T_c decreases. Here we report that in HTSCs it is the ratio z_A\Delta_m/T_c which is approximately constant, where \Delta_m is the maximum value of the d-wave gap, and z_A is the weight of the coherent excitations in the spectral function. This is highly unusual, since in nearly all phase transitions, T_c is determined by an energy scale alone. We further show that in the low-temperature limit, z_{\it A} increases monotonically with increasing doping x. The growth is linear, i.e. z_A(x)\propto x, in the underdoped to optimally doped regimes, and slows down in overdoped samples. The reduction of z_A with increasing temperature resembles that of the c-axis superfluid density.
Campuzano Juan-Carlos
Ding Haibing
Engelbrecht Jan R.
Hinks D. G.
Kadowaki Kazuo
No associations
LandOfFree
Coherent quasiparticle weight and its connection to high-T_c superconductivity from angle-resolved photoemission does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Coherent quasiparticle weight and its connection to high-T_c superconductivity from angle-resolved photoemission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coherent quasiparticle weight and its connection to high-T_c superconductivity from angle-resolved photoemission will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-407378