A Landauer formula for the current through a region of interacting electrons is derived using nonequilibrium Keldysh formalism. The case proportionate coupling to left and right leads, where takes an especially simple form, studied in more detail. Two particular examples interactions give rise novel effects are discussed: In Kondo regime, enhanced conductance predicted, while suppressed predicted tunneling quantum dot fractional Hall regime.

We consider a mesoscopic region coupled to two leads under the influence of external timedependent voltages. The time dependence is source and drain contacts, gates controlling tunnel-barrier heights, or that define region. derive, with Keldysh nonequilibrium-Green-function technique, formal expression for fully nonlinear, time-dependent current through system. analysis admits arbitary interactions in region, but are treated as noninteracting. For proportionate coupling leads, time-averaged...

NEC technical report 92-079-2-0077-1.

The conductance through a quantum dot is calculated via an Anderson model of site weakly coupled to ideal leads with on-site Coulomb interaction. As the chemical potential varied, peaks occur periodically in whenever electron added site. participation multiple electronic levels each peak explains anomalous temperature dependence heights observed recent narrow-channel experiments.

The infinite-U Anderson model is applied to transport through a quantum dot. current and density of states are obtained via the non-crossing approximation for two spin-degenerate levels weakly coupled leads. At low temperatures, Kondo peak in equilibrium strongly enhances linear-response conductance. Application finite voltage bias reduces conductance splits states. split peaks, one at each chemical potential, suppressed amplitude by dissipative lifetime. We estimate this lifetime...

In principle, density functional theory yields the correct ground-state densities and energies of electronic systems under action a static external potential. However, traditional approximations fail to include van der Waals between separated systems. This paper proposes practical procedure for remedying this difficulty. Our method allows seamless calculations small large intersystem distances. The asymptotic H-He He--He interactions are calculated as first illustration, with very accurate results.

Transport measurements of a Coulomb island, semiconductor dot small enough that interactions dominate transport are presented. At moderate magnetic fields (B=2--4 T) the amplitude and position Coulomb-regulated conductance peaks show distinct periodic structure as function B. This is shown to result from B dependence quantized single-particle energy states on island. Analysis successive used map out level spectrum island

We present a general formulation of the nonlinear, time-dependent current through small interacting region, where electron energies are changed by voltages. An exact solution is obtained for non-interacting case when elastic coupling to leads independent energy. Temporal phase coherence in double-barrier tunneling structure produces ``ringing" response voltage pulse, which can be observed experimentally dc-current varying pulse length train pulses. The nonlinear due an ac-bias also shows...

In Escherichia coli, division site selection is regulated in part by the Min-protein system. Oscillations of Min proteins from pole to every approximately 40 sec have been revealed vivo studies GFP fusions. The dynamic oscillatory structures produced proteins, including a ring MinE protein, compact polar zones MinD, and zebra-striped oscillations filamentous cells, remain unexplained. We show that oscillations, mutant phenotypes, can be accounted for vitro-observed interactions involving...

It is claimed that the abstract analytic continuation of hypercubic lattices to noninteger dimensionalities can be implemented explicitly by certain fractal low lacunarity. These are special examples Sierpinski carpets. Their being lacunarity means they arbitrarily close translationally invariant. The claim substantiated for Ising model in $D=1+\ensuremath{\epsilon}$ dimensions, and resistor network models with $1<D<2$.

Experiments on quantum point contacts have highlighted an anomalous conductance plateau around 0.7(2e(2)/h), with features suggestive of the Kondo effect. Here, Anderson model for transport through a contact analyzed in limit. Hybridization to band increases abruptly energy but decreases valence, so that background and temperature T(K) are dominated by different valence transitions. This accounts high residual above T(K). The explains observed gate-voltage, temperature, magnetic field,...

Transport measurements are used to study the quantized energy levels in a small electron gas, referred as Coulomb island. First, large-bias reveal excitation spectrum of Second, small-bias probe intrinsic line shape levels. Line shapes generally fit well by thermally broadened Lorentzians. In addition, decrease charging island is observed coupling its leads increased. This effect shown be consistent with dramatic increase one island-lead capacitances.

The conductance through two quantum dots in series is studied using general qualitative arguments and quantitative slave-boson mean-field theory. It demonstrated that measurements of the can explore phase diagram two-impurity Anderson model. Competition between Kondo effect interdot magnetic exchange leads to a two-plateau structure as function gate voltage or three peak versus tunneling.

The chemotaxis network in Escherichia coli is remarkable for its sensitivity to small relative changes the concentrations of multiple chemical signals. We present a model signal integration by mixed clusters interacting two-state chemoreceptors. Our results compare favorably obtained Sourjik and Berg with vivo fluorescence resonance energy transfer. Importantly, we identify two distinct regimes behavior, depending on energies states receptors. In regime I, coupling receptors leads high...

The effect of spin-orbit (SO) scattering in disordered mesoscopic systems is studied. In one dimension it shown that any spin-independent thermodynamic or transport quantity can be expressed terms the same absence SO scattering, but with an effective magnetic flux. This leads to universal reduction factors harmonics. particular, conductance and its fluctuations are interrelated, within beyond weak-localization theory. Generalizations higher dimensions discussed.

Significance The ParABS system is responsible for chromosome and plasmid segregation in many bacteria. A large, coherent ParB–DNA complex forms the partitioning module at heart of this machinery. Here we provide a simple theoretical model interacting proteins on DNA to elucidate structure complex. We show that both 3D bridging 1D spreading interactions between DNA-bound ParB are required ensure formation protein–DNA This combination protein–protein implies surface tension drives condensation...

Cells possess a multiplicity of non-membrane-bound compartments, which form via liquid-liquid phase separation. These condensates assemble and dissolve as needed to enable central cellular functions. One important class is those composed two associating polymer species that one-to-one specific bonds. What are the physical principles underlie separation in such systems? To address this question, we employed coarse-grained molecular dynamics simulations examine how boundaries depend on...

Entropy is a fundamental thermodynamic quantity indicative of the accessible degrees freedom in system. While it has been suggested that entropy mesoscopic system can yield nontrivial information on emergence exotic states, its measurement such small electron-number daunting task. Here we propose method to extract Coulomb-blockaded from transport measurements. We prove analytically and demonstrate numerically applicability arbitrary spectrum degeneracies. then apply our procedure...

Liquid-liquid phase separation is a fundamental mechanism underlying subcellular organization. Motivated by the striking observation that optogenetically generated droplets in nucleus display suppressed coarsening dynamics, we study impact of chromatin mechanics on droplet separation. We combine theory and simulation to show cross-linked can mechanically suppress droplets' coalescence ripening, as well quantitatively control their number, size, placement. Our results highlight role...

Abstract The Kondo effect is a cornerstone in the study of strongly correlated fermions. coherent exchange coupling conduction electrons to local magnetic moments gives rise cloud that screens impurity spin. Here we report on interplay between spin–orbit interaction and effect, can lead underscreened effects quantum dots bilayer graphene. More generally, introduce different experimental platform for studying physics. In contrast carbon nanotubes, where nanotube chirality determines breaking...

Superconductor–semiconductor hybrid systems play a crucial role in realizing nanoscale quantum devices, including qubits, Majorana bound states, and Kitaev chains. For such subgap states prominent their operation. In this paper, we study these via Coulomb tunneling spectroscopy through superconducting island defined semiconductor nanowire fully coated by superconductor. We systematically explore regimes ranging from an almost decoupled to the open configuration. weak-coupling regime,...

The ``Which Path?'' interferometer consists of an Aharonov-Bohm ring with a quantum dot (QD) built in one its arms, and additional point contact (QPC) located close to the QD. transmission coefficient QPC depends on charge state Hence acts as controllable measurement device for which path electron takes through ring. We calculate suppression oscillations is caused by both dephasing orthogonality catastrophe, i.e., respectively, real virtual electron-hole pair creation at QPC.

A simple non-interacting-electron model, combining local quantum tunneling and global classical percolation (due to a finite dephasing time at low temperatures), is introduced describe metal-insulator transition in two dimensions. It shown that many features of the experiments, such as exponential dependence resistance on temperature metallic side, linear exponent density, $e^2/h$ scale critical resistance, quenching phase by parallel magnetic field non-monotonic density perpendicular field,...