Biomedical subjects

J B Marston

Publications and source records attributed to J B Marston.

4 recordsLinked to original sources

PubMed2003

Broken time-reversal symmetry in strongly correlated ladder structures.

We provide, for the first time, in a doped strongly correlated system (two-leg ladder), a controlled theoretical demonstration of the existence of a state in which long-range ordered orbital currents are arranged in a staggered pattern, coexisting with a charge density wave. The method used is the highly accurate density-matrix renormalization group technique. This brings us closer to recent proposals that this order is realized in the enigmatic pseudogap phase of the cuprate high temperature superconductors.

Journal Article↗

PubMed2003

Thermally enhanced neutralization in hyperthermal energy ion scattering.

Neutralization probabilities are presented for hyperthermal energy Na+ ions scattered from a Cu(001) crystal as a function of surface temperature and scattered velocity. A large enhancement in neutralization is observed as the temperature is increased. Velocity-dependent charge transfer regimes are probed by varying the incident energy, with the most prominent surface temperature effects occurring at the lowest energies. The data agree well with results obtained from a model based on the Newns-Anderson Hamiltonian, where the effects of both temperature and velocity are incorporated.

Journal Article↗

PubMed2002

Staggered flux phase in a model of strongly correlated electrons.

We present numerical evidence for the existence of a staggered flux (SF) phase in the half-filled two-leg t-U-V-J ladder, with true long-range order in the countercirculating currents. The density-matrix renormalization-group finite-size scaling approach, generalized to describe complex-valued Hamil-tonians and wave functions, is employed. The SF phase exhibits robust currents at intermediate values of the interaction strength.

Journal Article↗

PubMed2002

Time-dependent density-matrix renormalization group: a systematic method for the study of quantum many-body out-of-equilibrium systems.

The density-matrix renormalization-group algorithm is extended to treat time-dependent problems. The method provides a systematic and robust tool to explore out-of-equilibrium phenomena in quantum many-body systems. We illustrate the method by showing that attractive interactions enhance the tunneling current between two Luttinger liquids, whereas repulsive interactions suppress it, in qualitative agreement with analytical predictions. Enhancement of the transport current through a quantum dot in the Kondo regime is also exhibited.

Journal Article↗