Related papers: Conductance-Phase Determination in Double Slit Tra…
We study the fidelity approach to quantum phase transitions (QPTs) and apply it to general thermal phase transitions (PTs). We analyze two particular cases: the Stoner-Hubbard itinerant electron model of magnetism and the BCS theory of…
Mesoscopic solid state Aharonov-Bohm interferometers have been used to measure the "intrinsic" phase, $\alpha_{QD}$, of the resonant quantum transmission amplitude through a quantum dot (QD). For a two-terminal "closed" interferometer,…
Gaussian linking of a semiclassical path of a charged particle with a magnetic flux tube is responsible for the Aharonov-Bohm effect, where one observes interference proportional to the magnitude of the enclosed flux. We construct quantum…
We report on the direct observation of the transmission phase shift through a Kondo correlated quantum dot by employing a new type of two-path interferometer. We observed a clear $\pi/2$-phase shift, which persists up to the Kondo…
We report on the phase measurements on a quantum dot containing a single electron in the Kondo regime. Transport takes place through a single orbital state. Although the conductance is far from the unitary limit, we measure for the first…
A unified theory for the current through a nanoscale region of interacting electrons connected to two leads which can be either ferromagnet or superconductor is presented, yielding Meir-Wingreen-type formulas when applied to specific…
Low-temperature transport properties of a lateral quantum dot formed by overlaying finger gates in a clean one-dimensional channel are investigated. Continuous and periodic oscillations superimposed upon ballistic conductance steps are…
Quantum Fourier transforms (QFT) have gained increased attention with the rise of quantum walks, boson sampling, and quantum metrology. Here we present and demonstrate a general technique that simplifies the construction of QFT…
Two interacting electrons in a harmonic oscillator potential under the influence of a perpendicular homogeneous magnetic field are considered. Analytic expressions are obtained for the energy spectrum of the two- and three-dimensional…
Numerical results are presented for transport properties of two coupled double-level quantum dots. The results strongly suggest that under appropriate circumstances the dots can develop a novel ferromagnetic (FM) correlation at…
We study electron transport through a closed Aharonov-Bohm interferometer containing two single-level quantum dots. The quantum-dot levels are coupled to each other indirectly via the leads. We find that this coupling yields signatures of…
The field-orientation dependent thermal conductivity of the heavy-fermion superconductor UPt$_3$ was measured down to very low temperatures and under magnetic fields throughout three distinct superconducting phases: A, B, and C phases. In…
We investigate the quantum transport dynamics of electrons in a multi-path Aharonov-Bohm interferometer comprising several parallel graphene nanoribbons. At low magnetic field strengths, the conductance displays a complex oscillatory…
We show that the observed evolution of the transmission phase through multi-electron quantum dots with more than approximately ten electrons, which shows a universal (i.e., independent of N) as yet unexplained behavior, is consistent with…
Fano lineshapes in resonant transmission in a quantum dot imply interference between localized and extended states. The influence of the charge accumulated at the localized levels, which screens the external gate voltage acting on the…
Phase transitions are characterized by a sharp change in the type of dynamics of microparticles, and their description usually requires quantum mechanics. Recently, a peculiar type of conductors was discovered in which two-dimensional (2D)…
Mesoscopic conductors are electronic systems of sizes in between nano- and micrometers, and often of reduced dimensionality. In the phase-coherent regime at low temperatures, the conductance of these devices is governed by quantum…
A double percolation transition is identified in a binary network composed of nanoparticles of magnesium diborade superconductor and chromium oxide half-metallic ferromagnet. Anomalously high-resistance or insulating state, as compared to…
This thesis describes the merging of the two fields of Coulomb drag and mesoscopic physics. The thesis presents a theory for Coulomb drag between two mesoscopic systems based on linear-response theory. The formalism expresses the drag in…
We study an electron distribution under a quasiperiodic potential in light of hyperuniformity, aiming to establish a classification and analysis method for aperiodic but orderly density distributions realized in, e.g., quasicrystals. Using…