Related papers: Optimizing the Cooper pair splitting efficiency in…
Superconductivity can be understood in terms of a phase transition from an uncorrelated electron gas to a condensate of Cooper pairs in which the relative phases of the constituent electrons are coherent over macroscopic length scales. The…
Based on the quantum two-body problem introduced in [arXiv:1604.06693] we consider bound pairs of electrons moving on the positive half-line. The analysis is motivated by the ground-breaking work of Cooper who identified the pairing of…
Under appropriate conditions, superconducting electronic circuits behave quantum mechanically, with properties that can be designed and controlled at will. We have realized an experiment in which a superconducting two-level system, playing…
Building on previous research on frequency allocation optimization for superconducting circuit quantum processors, this work incorporates several new techniques to improve overall solution quality. New features include tightening…
We put forward two efficient entanglement concentration protocols (ECPs) for distilling the maximally entangled NOON state from arbitrary less-entangled NOON state with only an auxiliary single photon. With the help of the weak cross-Kerr…
We propose a circuit comprising a linear array of three small-capacitance superconducting tunnel junctions with miniature resistors (R > R_Q = h/4e^2 = 6.5 kOhm) attached to the ends of this array. Owing to the Coulomb blockade effect and…
Single-charge tunneling in ultrasmall voltage biased SIS junctions in a high-impedance electromagnetic environment is considered. The Cooper pair current is calculated at T=0 on the basis of the elementary tunnel Hamiltonian for…
Hybrid quantum dot-oscillator systems have become attractive platforms to inspect quantum coherence effects at the nanoscale. Here, we investigate a Cooper-pair splitter setup consisting of two quantum dots, each linearly coupled to a local…
We analyze the quantum dynamics of two electromagnetic oscillators coupled in series to a voltage biased Josephson junction. When the applied voltage leads to a Josephson frequency across the junction which matches the sum of the two mode…
We present an entanglement concentration protocol for electrons based on their spins and their charges. The combination of an electronic polarizing beam splitter and a charge detector functions as a parity check device for two electrons,…
We report on the fabrication and metrology of superconducting caps for qubit circuits. As part of a 3D quantum integrated circuit architecture, a cap chip forms the upper half of an enclosure that provides isolation, increases vacuum…
We present an exactly solvable effective model of a double quantum dot coupled to superconducting leads. This model is a generalization of the well-known superconducting atomic limit approximation of the paradigmatic superconducting…
The promise of single Cooper pair quantum circuits based on tunnel junctions for metrology and quantum information applications is severely limited by the influence of "offset" charges - random, slowly drifting microscopic charges inherent…
We study a multi-terminal Josephson junction based on an interacting quantum dot coupled to $n$ superconducting BCS leads. Using an Anderson type model of a local level with an arbitrary onsite Coulomb repulsion, we uncover its surprising…
Entangled photon pairs are key to many novel applications in quantum technologies. Semiconductor quantum dots can be used as sources of on-demand, highly entangled photons. The fidelity to a fixed maximally entangled state is limited by the…
Junction systems of odd-frequency (OF) superconductors are investigated based on a mean-field Hamiltonian formalism. One-dimensional two-channel Kondo lattice (TCKL) is taken as a concrete example of OF superconductors. Properties of normal…
We characterize a pair of Cooper-pair boxes coupled with a fixed capacitor using spectroscopy and measurements of the ground-state quantum capacitance. We use the extracted parameters to estimate the concurrence, or degree of entanglement…
A practical source of high fidelity entangled photons is desirable for quantum information applications and exploring quantum physics. Semiconductor quantum dots have recently been shown to conveniently emit entangled light when driven…
We suggest a way to characterize the coherence of the split Cooper pairs emitted by a double-quantum-dot based Cooper pair splitter (CPS), by studying the radiative response of such a CPS inside a microwave cavity. The coherence of the…
There is growing evidence that the unconventional spatial inhomogeneities in the doped high-Tc superconductors are accompanied by the pairing of electrons, subsequent quantum phase transitions (QPTs), and condensation in coherent states. We…