Asymptotic entanglement capacity of the Ising and anisotropic Heisenberg interactions

We compute the asymptotic entanglement capacity of the Ising interaction ZZ, the anisotropic Heisenberg interaction XX + YY, and more generally, any two-qubit Hamiltonian with canonical form K = a XX + b YY. We also describe an entanglement assisted classical communication protocol using the Hamiltonian K with rate equal to the asymptotic entanglement capacity.Comment: 5 pages, 1 figure; minor corrections, conjecture adde

A comparison of two magnetic ultra-cold neutron trapping concepts using a Halbach-octupole array

This paper describes a new magnetic trap for ultra-cold neutrons (UCNs) made from a 1.2 m long Halbach-octupole array of permanent magnets with an inner bore radius of 47 mm combined with an assembly of superconducting end coils and bias field solenoid. The use of the trap in a vertical, magneto-gravitational and a horizontal setup are compared in terms of the effective volume and ability to control key systematic effects that need to be addressed in high precision neutron lifetime measurements

Study program for encapsulation materials interface for low-cost solar array

The service integrity of the bonded interface in solar cell modules used in solar arrays is addressed. The development of AC impedance as a nondestructive evaluation (NDE) methodology for solar arrays is reported along with development of corrosion models and materials selection criteria for corrosion resistant interfaces

Heuristic derivation of continuum kinetic equations from microscopic dynamics

We present an approximate and heuristic scheme for the derivation of continuum kinetic equations from microscopic dynamics for stochastic, interacting systems. The method consists of a mean-field type, decoupled approximation of the master equation followed by the `naive' continuum limit. The Ising model and driven diffusive systems are used as illustrations. The equations derived are in agreement with other approaches, and consequences of the microscopic dependences of coarse-grained parameters compare favorably with exact or high-temperature expansions. The method is valuable when more systematic and rigorous approaches fail, and when microscopic inputs in the continuum theory are desirable.Comment: 7 pages, RevTeX, two-column, 4 PS figures include

One Country, Two Systems: Theory into Practice

The Hong Kong Special Administrative Region was established on July 1, 1997, when the former colony was handed over by Britain to China. Thereafter the policy of One Country, Two Systems began as dictated by the Basic Law. This article examines the evolution of the One Country, Two Systems policy and discusses how this policy has been reflected in the Basic Law. As any change in the Basic Law may affect the implementation of this policy, and perhaps the stability and prosperity of Hong Kong, this article also analyses the scheme, policies and rules in relation to interpreting and amending the Basic Law. It advocates for learning from the experience of other common law jurisdictions and recommends adopting the principles of consistency, progressiveness and foreseeability in interpreting the Basic Law