Related papers: Measuring charge based quantum bits by a supercond…
The act of measurement bridges the quantum and classical worlds by projecting a superposition of possible states into a single, albeit probabilistic, outcome. The time-scale of this "instantaneous" process can be stretched using weak…
In this review, we discuss recent experiments that investigate how the quantum sate of a superconducting qubit evolves during measurement. We provide a pedagogical overview of the measurement process, when the qubit is dispersively coupled…
We propose superconducting-semiconducting (super-semi) qubit and coupler designs based on high-quality, compact through-silicon vias (TSVs). An interposer "probe" wafer containing TSVs is used to contact a sample wafer with, for example, a…
Transistors, regardless of their size, rely on electrical gates to control the conductance between source and drain contacts. In atomic-scale transistors, this conductance is exquisitely sensitive to single electrons hopping via individual…
We propose to continuously monitor a charge qubit by utilizing a T-shaped double quantum dot detector, in which the qubit and double dot are arranged in such a unique way that the detector turns out to be particularly susceptible to the…
We demonstrate single-charge occupation of ambipolar quantum dots in silicon via charge sensing. We have fabricated ambipolar quantum dot (QD) devices in a silicon metal-oxide-semiconductor heterostructure comprising a single-electron…
We have developed a detailed experimental study of a single-electron transistor in a strong tunneling regime. Although weakened by strong charge fluctuations, Coulomb effects were found to persist in all samples including one with the…
Superconducting circuits with embedded symmetries are good candidates to robustly protect quantum information from dominant error channels. The $\cos(2\varphi)$ qubit, consisting of an island shunted to ground through a tunneling element…
Decoherence errors arising from noisy environments remain a central obstacle to progress in quantum computation and information processing. Quantum error correction (QEC) based on the Gottesman-Kitaev-Preskill (GKP) protocol offers a…
The Hilbert space of a physical qubit typically features more than two energy levels. Using states outside the qubit subspace can provide advantages in quantum computation. To benefit from these advantages, individual states of the…
We consider a system of superconducting grains embedded in a normal metal. At zero temperature this system exhibits a quantum superconductor-normal metal phase transition. This transition can take place at arbitrarily large conductance of…
Superconducting quantum circuits must be designed carefully to avoid dissipation from coupling to external control circuitry. Here we introduce the concept of current transformation to quantify coupling to the environment. We test this…
Quantum device measurements are powerful tools to probe dark matter interactions. Among these, transmon qubits stand out for their ability to suppress external noise while remaining highly sensitive to tiny energy deposits. Ambient galactic…
Recent experiments with superconducting qubits are motivated by the goal of fabricating a quantum computer, but at the same time they illuminate the more fundamental aspects of quantum mechanics. In this paper we analyze the physics of…
We propose a new solid state implementation of a quantum computer (quputer) using ballistic single electrons as flying qubits in 1D nanowires. We use a single electron pump (SEP) to prepare the initial state and a single electron transistor…
A numerical renormalization-group survey of the zero-bias electrical conductance through a quantum dot embedded in the conduction path of a nanodevice is reported. The results are examined in the light of a recently derived linear mapping…
We report on measurements on a sample consisting of two nominally identical single-electron transistors the islands of which are coupled capacitively. One transistor at a time is operated as electron box. The remaining transistor is used as…
We describe quantum phase transitions in superconducting complex oxides which could be tuned by electrostatic charge transfer. Using a simple model for the superconductivity of a thin film or surface of a bulk copper oxide, we show that…
Metallic nanoparticles offer possibilities to build basic electric devices with new functionality and improved performance. Due to the small volume and the resulting low self-capacitance, each single nanoparticle exhibits a high charging…
We report a robust process for fabrication of surface-gated Si/SiGe quantum dots (QDs) with an integrated superconducting single-electron transistor (S-SET) charge sensor. A combination of a deep mesa etch and AlOx backfill is used to…