The density-matrix renormalization group (DMRG) is a numerical algorithm for the efficient truncation of the Hilbert space of low-dimensional strongly correlated quantum systems based on a rather general decimation prescription. This algorithm has achieved unprecedented precision in the description of one-dimensional quantum systems. It has therefore quickly become the method of choice for numerical studies of such systems. Its applications to the calculation of static, dynamic, and thermodynamic quantities in these systems are reviewed here. The potential of DMRG applications in the fields of two-dimensional quantum systems, quantum chemistry, three-dimensional small grains, nuclear physics, equilibrium and nonequilibrium statistical physics, and time-dependent phenomena is also discussed. This review additionally considers the theoretical foundations of the method, examining its relationship to matrix-product states and the quantum information content of the density matrices generated by the DMRG.

http://www.physics.udel.edu/~bnikolic/QTTG/NOTES/DMRG/SCHOLLWOCK=RMP_dmrg.pdf

The density-matrix renormalization group

Physical Review B

The structural properties of free nanoclusters are reviewed. Special attention is paid to the interplay of energetic, thermodynamic, and kinetic factors in the explanation of cluster structures that are actually observed in experiments. The review starts with a brief summary of the experimental methods for the production of free nanoclusters and then considers theoretical and simulation issues, always discussed in close connection with the experimental results. The energetic properties are treated first, along with methods for modeling elementary constituent interactions and for global optimization on the cluster potential-energy surface. After that, a section on cluster thermodynamics follows. The discussion includes the analysis of solid-solid structural transitions and of melting, with its size dependence. The last section is devoted to the growth kinetics of free nanoclusters and treats the growth of isolated clusters and their coalescence. Several specific systems are analyzed.

/pdf/structural-properties-of-nanoclusters-energetic-56vj4t3ucw.pdf

Structural properties of nanoclusters: Energetic, thermodynamic, and kinetic effects

The isolation of graphene has triggered an avalanche of studies into the spin-dependent physical properties of this material, as well as graphene-based spintronic devices Here we review the experimental and theoretical state-of-art concerning spin injection and transport, defect-induced magnetic moments, spin-orbit coupling and spin relaxation in graphene Future research in graphene spintronics will need to address the development of applications such as spin transistors and spin logic devices, as well as exotic physical properties including topological states and proximity-induced phenomena in graphene and other 2D materials

Graphene Spintronics

Thank you very much for reading electronic transport in mesoscopic systems. Maybe you have knowledge that, people have look numerous times for their favorite readings like this electronic transport in mesoscopic systems, but end up in harmful downloads. Rather than reading a good book with a cup of tea in the afternoon, instead they juggled with some harmful bugs inside their computer. electronic transport in mesoscopic systems is available in our book collection an online access to it is set as public so you can get it instantly. Our book servers spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the electronic transport in mesoscopic systems is universally compatible with any devices to read.

Electronic Transport In Mesoscopic Systems

We present a method to compute dynamical correlation functions in quantum many-body systems at zero temperature. The ground state of a finite system is evaluated exactly by a modified Lanczos method and from it the real-frequency correlation functions are obtained by a projective technique for the memory-function formalism. We apply the method to the density-density correlation function of a one-dimensional spinless fermion system. Exact results are recovered in the noninteracting limit; in the strong-coupling limit our results are compared with Monte Carlo simulation and analytical approximations.

Dynamical properties of quantum many-body systems at zero temperature

We consider a ballistic Josephson junction with a quantum point contact in a two-dimensional electron gas with Rashba spin-orbit coupling. The point contact acts as a spin filter when embedded in a circuit with normal electrodes. We show that with an in-plane external magnetic field an anomalous supercurrent appears even for zero phase difference between the superconducting electrodes. In addition, the external field induces large critical current asymmetries between the two flow directions, leading to supercurrent rectifying effects.

/pdf/anomalous-josephson-current-in-junctions-with-spin-707b5o0ztc.pdf

Anomalous Josephson current in junctions with spin polarizing quantum point contacts.

Recent experiments have demonstrated the efficacy of chiral helically shaped molecules in polarizing the scattered electron spin, an effect termed chiral-induced spin selectivity. Here we solve a simple tight-binding model for electron transport through a single helical molecule, with spin-orbit interactions on the bonds along the helix. Quantum interference is introduced via additional electron hopping between neighboring sites in the direction of the helix axis. When the helix is connected to two one-dimensional single-mode leads, time-reversal symmetry prevents spin polarization of the outgoing electrons. One possible way to retrieve such a polarization is to allow leakage of electrons from the helix to the environment, via additional outgoing leads. Technically, the leakage generates complex site self-energies, which break unitarity. As a result, the electron waves in the helix become evanescent, with different decay lengths for different spin polarizations, yielding a net spin polarization of the outgoing electrons, which increases with the length of the helix (as observed experimentally). A maximal polarization can be measured at a finite angle away from the helix axis.

Spin-dependent transport through a chiral molecule in the presence of spin-orbit interaction and nonunitary effects

Publisher Summary Superconductivity (SC) and charge-density wave (CDW) are the two most well-known cases of broken symmetry in a solid, which require an effective attractive electron–electron interaction. That interaction is normally provided by a phonon-mediated mechanism. It is therefore to be expected that systems in which CDWs have been experimentally observed also exhibit SC at very low temperatures. The tendencies toward the formation of SC and CDW are to a certain degree opposing one another. While the SC state has infinite conductivity and a Meissner effect, the CDW state, for large enough interactions, produces a semiconductor gap in the spectrum and a nonconducting state. From a microscopic point of view, on the other hand, the SC state arises from electron–electron coupling into Cooper pairs and the CDW state arises from electron-hole coupling and charge redistribution. These two effects are in principle independent of one another. This chapter discusses the interdependence of the SC and CDW states.

Superconductivity and charge-density waves

We study a generalized Hubbard Hamiltonian which includes the Cu and O orbitals in the CuO/sub 2/ planes of high-/ital T//sub /ital c// superconductors. We use slave-boson technique to account for the intra- and interatomic correlations. In the saddle-point approximation we obtain the metal-insulator phase diagram and conclude that, for one hole per unit cell in the CuO/sub 2/ plane, La/sub 2/CuO/sub 4/ is a charge-transfer insulator. Our results show that doping produces a rapid metallization of the system and destroys antiferromagnetic order. Transport properties and mechanism for superconductivity are briefly discussed.

C. A. Balseiro

Papers

Dynamical properties of quantum many-body systems at zero temperature

Anomalous Josephson current in junctions with spin polarizing quantum point contacts.

Spin-dependent transport through a chiral molecule in the presence of spin-orbit interaction and nonunitary effects

Superconductivity and charge-density waves

Electronic properties of high-Tc superconductors.