Physics of the Pseudogap State: Spin-Charge Locking

The properties of the pseudogap phase above Tc of the high-Tc cuprate superconductors are described by showing that the Anderson-Nambu SU(2) spinors of an RVB spin gap 'lock' to those of the electron charge system because of the resulting improvement of kinetic energy. This enormously extends the range of the vortex liquid state in these materials. As a result it is not clear that the spinons are ever truly deconfined. A heuristic description of the electrodynamics of this pseudogap-vortex liquid state is proposed.Comment: Submitted to Phys Rev Letter

Four-phase differential phase shift resolver

Two systems have been developed to resolve phase uncertainty without transmitting reference signals. In both methods signal is impressed on carrier as differential, rather than absolute, phase shift. At the receiver four-phase demodulation and logic process unambiguously resolves differential phase shift of input carrier

Differential phase shift keyed signal resolver

A differential phase shift keyed signal resolver resolves the differential phase shift in the incoming signal to determine the data content thereof overcoming phase uncertainty without requiring a transmitted reference signal

Differential phase shift keyed communication system

A communication system using differential phase-shift-keying (DPSK) transmits and receives binary data without requiring timing or phase reference signals. The system encodes and modulates the data at the transmitter, and decodes and demodulates the data at the receiver, without ambiguity as to the data content

Causality-based criteria for a negative refractive index must be used with care

Using the principle of causality as expressed in the Kramers-Kronig relations, we derive a generalized criterion for a negative refractive index that admits imperfect transparency at an observation frequency $\omega$. It also allows us to relate the global properties of the loss (i.e. its frequency response) to its local behaviour at $\omega$. However, causality-based criteria rely the on the group velocity, not the Poynting vector. Since the two are not equivalent, we provide some simple examples to compare the two criteria.Comment: slightly longer version of published PR

What can be learned from binding energy differences about nuclear structure: the example of delta V_{pn}

We perform an analysis of a binding energy difference called delta V_{pn}(N,Z) =- 1/4(E(Z,N)-E(Z,N-2)-E(Z-2,N)+ E(Z-2,N-2) in the framework of a realistic nuclear model. Using the angular-momentum and particle-number projected generator coordinate method and the Skyrme interaction SLy4, we analyze the contribution brought to delta V_{pn} by static deformation and dynamic fluctuations around the mean-field ground state. Our method gives a good overall description of delta V_{pn} throughout the chart of nuclei with the exception of the anomaly related to the Wigner energy along the N=Z line. The main conclusions of our analysis are that (i) the structures seen in the systematics of delta V_{pn} throughout the chart of nuclei can be easily explained combining a smooth background related to the symmetry energy and correlation energies due to deformation and collective fluctuations; (ii) the characteristic pattern of delta V_{pn} around a doubly-magic nucleus is a trivial consequence of the asymmetric definition of delta V_{pn}, and not due to a the different structure of these nuclei; (iii) delta V_{pn} does not provide a very reliable indicator for structural changes; (iv) \delta V_{pn} does not provide a reliable measure of the proton-neutron interaction in the nuclear EDF, neither of that between the last filled orbits, nor of the one summed over all orbits; (v) delta V_{pn} does not provide a conclusive benchmark for nuclear EDF methods that is superior or complementary to other mass filters such as two-nucleon separation energies or Q values.Comment: 19 pages and 12 figure