arXiv subjects

Ming-Lun Chen

Publications and source records attributed to Ming-Lun Chen.

3 recordsLinked to original sources

arXiv2014

A pairing hypothesis based on resonating valence bond state for hole doped copper oxide high temperature superconductors

To explain the high-temperature superconductivity of hole-doped copper-oxide high-temperature superconductors (HDCO-HTSCs), Anderson proposed a theory: (A) the pseudogap state is a resonating valence-bond (RVB) state below T* and (B) the RVB state translates itself into high-temperature superconducting state below Tc. In this paper we abandon Anderson theory B but still retain Anderson theory A and add three new hypotheses. Jointed three hypotheses with Anderson theory A, we construct an effective Hamiltonian of HDCO-HTSCs and explain why Tc-line is a dome in phase diagram and why HDCO-HTSCs have a higher Tc than that of conventional superconductors.

cond-mat.supr-con↗

arXiv2008

Decoherence of the Kondo Singlet Caused by Phase-sensitive Detection

We investigate the dephasing effect of the Kondo singlet in an Aharonov-Bohm interferometer with a quantum dot coupling to left and right electrodes. By employing the cluster expansions, the equations of motion of Green functions are transformed into the corresponding equation of motion of connected Green functions, which contains the correlation of two conduction electrons beyond the Lacroix approximation. With the method we show that the Kondo resonance is suppressed by phase-sensitive detection of Aharonov-Bohm interferometer. Our numerical results have provided a qualitative explanation with the anomalous features observed in a recent experiment by Avinun-Kalish \emph{et al}. [Phys. Rev. Lett. \textbf{92}, 156801 (2004)].

cond-mat.str-el↗

arXiv2006

Implementation of qutrit-based quantum information processing via state-dependent forces on trapped ions

We propose a scheme to realize quantum logic and entanglement for qutrit systems via state-dependent forces on trapped ions. By exploiting the laser-ion coupling in the presence of Coulomb interactions, the set of quantum gate operations including the conditional phase shifts on two qutrits as well as arbitrary SU(3) rotations on single qutrits are derived for universal quantum manipulation. As an illustration, we demonstrate in detail how these gate resources could be used to generate the maximally entangled state of two qutrits. Besides being insensitive to vibrational heating of the trapped ions, the present scheme is also shown to be scalable through designing appropriately the pulse configuration of the laser-ion interactions.

quant-ph↗