Some Thoughts upon Long-Range Interaction and Entangled States

The problems of long-range interaction and associated questions on entangled states are reconsidered in terms of a recently developed revised quantum electrodynamic theory by the author, as being applied to subatomic systems. There are indications that the theories of relativity and quantum mechanics do not necessarily have to be in conflict. But more investigations are required for a full understanding to be obtained on these problems.

From self-assembly to quantum guiding: A review of magnetic atomic structures on noble metal surfaces

Recent advances in the study of magnetic atomic structures on noble metal surfaces are reviewed. These include one- dimensional strings, two-dimensional hexagonal superlattices, and novel structures stabilized by quantum guiding. The combined techniques of low-temperature scanning tunneling microscopy, kinetic Monte Carlo simulations, and ab initio calculations reveal that surface-state-mediated adatom-step and adatom-adatom interactions are the driving forces for self- assembly of these structures. The formation conditions are further discussed by comparing various experimental systems and the kinetic Monte Carlo simulations. Using scanning tunneling spectroscopy and tight-binding calculations together, we reveal that the spectra of these well-ordered structures have characteristic peaks induced by electronic scattering processes of the atoms within the local environment. Moreover, it is demonstrated that quantum confinement by means of nano-size corrals has significant influence on adatom diffusion and self-assembly, leading to a quantum-guided self-assembly.

Quantum Correlation in Matrix Product States of One-Dimensional Spin Chains

For our proposed composite parity-conserved matrix product state(MPS), if only a spin block length is larger than 1, any two such spin blocks have correlation including classical correlation and quantum correlation. Both the total correlation and the classical correlation become larger than that in any subcomponent; while the quantum correlations of the two nearest-neighbor spin blocks and the two next-nearest-neighbor spin blocks become smaller and for other conditions the quantum correlation becomes larger, i.e., the increase or the production of the long-range quantum correlation is at the cost of reducing the short-range quantum correlation, which deserves to be investigated in the future; and the ration of the quantum correlation to the total correlation monotonically decreases to a steady value as the spacing spin length increasing.

Off-diagonal long-range order of the wave function in terms of the alternate molecular bonding geminals

It is shown that in the quantum structural approach to high-Tc superconductivity, the wave function in terms of the alternate molecular bonding geminals possesses off-diagonal long-range order (ODLRO).

Coupling and readout of semiconductor quantum dots with a superconducting microwave resonator

In a circuit quantum electrodynamics(circuit QED) architecture, the microwave resonator could be used to couple and probe qubits. The long-range coupling and information transfer between nonlocal qubits can be performed via photons trapped in a microwave resonator, promising an effective approach for scaling up solid-state qubits. A series of important advances in the hybrid system composed of a microwave resonator and semiconductor qubits have been achieved in recent years. For instance,with applications of high-impedance microwave resonators, the strong coupling regime between charge/spin qubits and a microwave resonator has been reached. Simultaneously, resonator-based dispersive readout and single-shot readout to probe the qubit state have been further improved due to the increase of the coupling strength. Here, we briefly introduce this hybrid system related to the progress and fruits in achieving the strong coupling between charge/spin qubits in double quantum dots(DQDs)and the resonator, the long-range coupling between qubits, and also the applications of the resonator for qubit state readout.

Quantum phase transitions in matrix product states of one-dimensional spin-(1/2) chains

For the matrix product system of a one-dimensional spin-1/2 chain, we present a new model of quantum2 phase transitions and find that in the thermodynamic limit, both sides of the critical point are respectively described by phases ｜Ψa 〉=｜1··· 1 representing all particles spin up and ｜Ψb 〉=｜0··· 0 representing all particles spin down, while the phase transition point is an isolated intermediate-coupling point where√ the two phases coexist equally, which is2 described by the so-called N-qubit maximally entangled GHZ state ｜Ψpt =√2/2（｜1··· 1 ＋｜0··· 0）. At the critical point,2the physical quantities including the entanglement are not discontinuous and the matrix product system has longrange correlation and N-qubit maximal entanglement. We believe that our work is helpful for having a comprehensive understanding of quantum phase transitions in matrix product states of one-dimensional spin chains and of potential directive significance to the preparation and control of one-dimensional spin lattice models with stable coherence and N-qubit maximal entanglement.

Quantum phase transitions in matrix product states of one-dimensional spin-1 chains

We present a new model of quantum phase transitions in matrix product systems of one-dimensional spin-1 chains and study the phases coexistence phenomenon. We find that in the thermodynamic limit the proposed system has three different quantum phases and by adjusting the control parameters we are able to realize any phase, any two phases equal coexistence and the three phases equM coexistence. At every critical point the physical quantities including the entanglement are not discontinuous and the matrix product system has long-range correlation and N-spin maximal entanglement. We believe that our work is helpful for having a comprehensive understanding of quantum phase transitions in matrix product states of one-dimensional spin chains and of certain directive significance to the preparation and control of one-dimensional spin lattice models with stable coherence and N-spin maximal entanglement.

利用量子对应态原理预测正仲氢输运性质

基于量子对应态原理并考虑氢同分异构体之间的结构差异,建立了适用于预测低温正氢与仲氢输运参数的数学模型,明确了对比黏度和对比导热系数与对比德布罗意波长之间的线性关系,并使用所建立数学模型预测了正氢与仲氢的黏度与导热系数。通过对计算结果的检验分析,发现量子对应态原理方法可以较准确地预测温度20100 K及压力0.0110 MPa范围内正氢、仲氢的黏度及导热系数。压力对模型的预测精度影响显著,当环境压力小于1 MPa时,对应态原理预测误差基本控制在6%以内。进一步修正模型中的物性常数修正有望提高对应态原理预测精度。