Biomedical subjects

M J Rozenberg

Publications and source records attributed to M J Rozenberg.

3 recordsLinked to original sources

PubMed2004

Nonvolatile memory with multilevel switching: a basic model.

There is a current upsurge in research on nonvolatile two-terminal resistance random access memory (RRAM) for next generation electronic applications. The RRAM is composed of a simple sandwich of a semiconductor with two metal electrodes. We introduce here an initial model for RRAM with the assumption that the semiconducting part has a nonpercolating domain structure. We solve the model using numerical simulations and the basic carrier transfer mechanism is unveiled in detail. Our model captures three key features observed in experiments: multilevel switchability of the resistance, its memory retention, and hysteretic behavior in the current-voltage curve.

Journal Article↗

PubMed2002

Compressibility divergence and the finite temperature Mott transition.

In the context of the dynamical mean-field theory (DMFT) of the Hubbard model, we study the behavior of the compressibility near the density driven Mott transition at finite temperatures. We demonstrate this divergence using DMFT and quantum Monte Carlo simulations in the one-band and the two-band Hubbard model. We supplement this result with considerations based on the Landau theory framework, and discuss the relevance of our results to the alpha-gamma end point in cerium.

Journal Article↗

PubMed2001

Dynamical response of quantum spin-glass models at t = 0.

We study the behavior of two archetypal quantum spin glasses at T = 0 by exact diagonalization techniques: the random Ising model in a transverse field and the random Heisenberg model. The behavior of the dynamical spin response is obtained in the spin-glass ordered phase. In both models it is gapless and has the general form chi(")(omega) = qdelta(omega)+chi(")(reg)(omega), with chi(")(reg)(omega) approximately omega for the Ising and chi(")(reg)(omega) approximately const for the Heisenberg, at low frequencies. The method provides new insight to the physical nature of the low-lying excitations.

Journal Article↗