Recent important progresses in the filed of HTSCs
The isotope effect (IE) on Tc of optimally doped HTSCs (α=dlnTc/dlnM <0.1) is small in comparison with the conventional BCS superconductors (α~0.5), an evidence that usually used against the phonon mediated pairing in HTSCs. However, the ARPES kink is one of the strongest evidence that there is strong electron-phonon coupling in HTSCs. To confirm this, [...]
One of the most important issues related to the mechanism of superconductivity in HTSCs is the role of electron-phonon (el-ph) interaction in this mechanism for such a strongly correlated electron systems. A group of scientists from the US and Japan have revealed a strong experimental evidence for existence of the strong electron-phonon interaction in these [...]
To address the relation between the anomalous behaviors observed in ARPES spectra and the charge ordering in the STM measurements of the HTSCs, a group of the US scientists in collaboration with Japanese scientists have been investigated this situation in Ca2-xNaxCuO2Cl2 (Na-CCOC). They have measured the ARPES spectra of Na-CCOC with x=0.05, 0.10, 0.12 (Tc=0, [...]
A group of scientists from United States have investigated the ground state of pesudogap by ARPES measurements of La2-xSrxCuO4, in x=1/8 concentration, where the superconductivity suppressed strongly and the system has static spin and charge orders. The main idea of this study is to clear the origin of pseudogap in HTSCs, which have been previously [...]
Some scientists from United States, Japan, and Canada in collaboration with each other have discovered two different Fermi momentum-dependent gaps related to the superconducting state and pseudogap. They have measured the ARPES spectra of deeply underdoped Bi2Sr2Ca1-xYxCu2O8 crystals, with Tc of 30-50 K. Analyzing the data shows two distinct energy gaps with different characteristics:
1) [...]
