Dynamic magnetoconductance fluctuations and oscillations in mesoscopic wires and rings

Abstract

Using a finite-frequency recursive Green's function technique, we calculate the dynamic magneto-conductance fluctuations and oscillations in disordered mesoscopic normal metal systems, incorporating inter-particle Coulomb interactions within a self-consistent potential method. In a disordered metal wire, we observe ergodic behavior in the dynamic conductance fluctuations. At low ω, the real part of the conductance fluctuations is essentially given by the dc universal conductance fluctuations while the imaginary part increases linearly from zero, but for ω greater than the Thouless energy and temperature, the fluctuations decrease as ω −1/2 . Similar frequency-dependent behavior is found for the Aharonov-Bohm oscillations in a metal ring. However, the Al'tshuler-Aronov-Spivak oscillations, which predominate at high temperatures or in rings with many channels, are strongly suppressed at high frequencies, leading to interesting crossover effects in the ω-dependence of the magneto-conductance oscillations.

Time-dependent current partition in mesoscopic conductors

“…Such experiments would highlight that these coefficients should not be treated as geometrical constants, but like conductances, represent information on the physical properties of samples. An electro-chemical emittance has been measured in the experiment by Pieper and Price [13] and has been shown to exhibit AB-oscillations over the entire accessible range of frequencies [15]. AB-oscillations in a capacitance coefficient are likely to be an even more challenging task since the AB effect in the capacitance is likely only a small correction to a geometrical capacitance.…”

“…A recent experiment by Pieper and Price determines both the real and imaginary part of the ac-conductance of a metallic diffusive Aharonov-Bohm loop over a wide range of frequencies [13]. A theoretical discussion of these results is presented by Pieper and Price [14] using a diagramatic approach and by Liu et al [15] using the results of Ref. [8].…”

Resonant Photon-Assisted Tunneling through a Double Quantum Dot: An Electron Pump from Spatial Rabi Oscillations

“…While the phenomena of Ref. [2] found a natural explanation within linear response theory [3,4], many time-dependent phenomena, such as electron pumps [5], photon-assisted tunneling [6][7][8][9][10], and lasers [11], necessitate a nonlinear analysis.…”

Emittance fluctuations in a mesoscopic diffusive conductor

“…5 Theoretical investigations have been carried out on a number of topics related to fluctuations of dynamic conductance, including the fluctuating admittance of chaotic cavities, 6,7 random matrix analysis of capacitance distribution, 8 transfer matrix studies of low frequency quasi-one-dimensional systems, 9 and dynamic magnetoconductance fluctuations. 10 In this paper, we present a theoretical investigation of sample-to-sample statistical properties of the low frequency admittance. Our analysis is based on the theory of Büttiker, Prêtre, and Thomas, 3 and our calculation is from first principles by evaluating the internal potential response from the density of states 11 ͑see below͒, rather than using the approximate constant capacitance charging model.…”