Kai-Yu Yang

On the Origin of the Checkerboard Pattern in Scanning Tunneling Microscopy Maps of Underdoped Cuprate Superconductors (2009)

Yang, Kai-Yu, Chen, Wei-Qiang, Rice, T. M., Zhang, Fu-Chun

The checkerboard pattern in the differential conductance maps on underdoped cuprates appears when the STM is placed above the O-sites in the outermost CuO$_{\text{2}}$-plane. In this position the...

Quasiparticles in the Pseudogap Phase of Underdoped Cuprate (2008)

Yang, Kai-Yu, Yang, H. B., Johnson, P. D., Rice, T. M., Zhang, Fu-Chun

Recent angle resolved photoemission and scanning tunneling microscopy measurements on underdoped cuprates have yielded new spectroscopic information on quasiparticles in the pseudogap phase. New...

Theory for Superconductivity in Iron Pnictides at Large Coulomb U Limit (2008)

Chen, Wei-Qiang, Yang, Kai-Yu, Zhou, Yi, Zhang, Fu-Chun

Superconductivity in iron pnictides is studied by using a two-orbital Hubbard model in the large U limit. The Coulomb repulsion induces an orbital-dependent pairing between charge carriers. The...

Nature of Stripes in the Generalized t-J Model Applied to The Cuprate Superconductors (2008)

Yang, Kai-Yu, Chen, Wei-Qiang, Rice, T. M., Sigrist, M., Zhang, Fu-Chun

Recent transport properties on the stripe phase in La$_{\text{1.875}}$Ba$_{\text{01.25}}$CuO$_{\text{4}}$ by Li \textit{et al.} found 2-dimensional superconductivity over a wide temperature range...

Quantum Oscillations in Magnetic Field Induced Antiferromagnetic Phase of Underdoped Cuprates : Application to Ortho-II YBa2Cu3O6.5 (2007)

Chen, Wei-Qiang, Yang, Kai-Yu, Rice, T. M., Zhang, F. C.

Magnetic field induced antiferromagnetic phase of the underdoped cuprates is studied within the t-t'-J model. A magnetic field suppresses the pairing amplitude, which in turn may induce...

Effect of superlattice modulation of electronic parameters on superconducting density of states in cuprate superconductors (2007)

Yang, Kai-Yu, Rice, T. M., Zhang, Fu-Chun

Recent scanning tunneling microscopy on BSCCO 2212 has revealed a substantial spatial supermodulation of the energy gap in the superconducting state. We propose that this gap modulation is due to the...

Low energy physical properties of high-Tc superconducting Cu oxides: A comparison between the resonating valence bond and experiments (2006)

Yang, Kai-Yu, Shih, C. T., Chou, C. P., Huang, S. M., Lee, T. K., Xiang, T., ...

In a recent review by Anderson and coworkers\cite{Vanilla}, it was pointed out that an early resonating valence bond (RVB) theory is able to explain a number of unusual properties of high temperature...

A Phenomenological Theory of The Pseudogap State (2006)

Yang, Kai-Yu, Rice, T. M., Zhang, Fu-Chun

An ansatz is proposed for the coherent part of the single particle Green's function in a doped resonant valence bond (RVB) state by, analogy with the form derived by Konik and coworkers for a doped...