Recent important progresses in the filed of HTSCs
The observed sharp ‘kink’ in the ARPES has been related to the phonon or magnetic mode as a possible signature of the force that create the superconducting state in HTSCs. A group of scientists from Canada and the USA have studied this situation by Fourier-transform infrared (FTIR) spectroscopy of optimally doped (Tc=96 K) and highly [...]
Dramatic changes in the magnetic excitation spectrum by going to the superconducting state of HTSCs, known as the “resonance” peak, have been considered as a strong evidence for the magnetic pairing mechanism of superconductivity in these systems. The resonance peak occurs at Eres=41 and 34 meV [at q=(0.5, 0.5) in the CuO2 reciprocal lattice units [...]
Determining of bosons (phonon or magnetic modes) which play an important role in the electron-boson interaction (EBI) and making pairs in HTSCs has been complicated, because different aspects of experimental evidences such as ARPES and optical spectroscopy could be interpreted by one of these bosons. Recently atomic-resolution STM study of Bi-2212 has been done by [...]
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 [...]
“Quantum protector” (QP) is a macroscopic quantum (for example quantum Hall effect and flux quantization of superconductivity) that is usually unaffected by imperfection, impurities and thermal fluctuations. In this state the excitations are collective excitations of the whole system rather than usual elementary excitations in many-body systems such as in Fermi liquid. P.W. Anderson believes that [...]
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, [...]
