Related papers: A fast and large bandwidth superconducting variabl…
In superconducting electronics, the ability to control the frequency of microwave wave packets is crucial for several applications, such as the operation of superconducting quantum processors and the readout of superconducting sensors. We…
Cryogenic microwave measurement of superconducting quantum devices is complicated by the packaging required to connect devices to control and readout circuitry. In this work, we outline the design and experimental demonstration of a…
A directional superconducting parametric amplifier in the GHz frequency range is designed and analyzed, suitable for low-power read-out of microwave kinetic inductance detectors employed in astrophysics and when combined with a…
Nonreciprocal microwave devices, such as circulators, are useful in routing quantum signals in quantum networks and protecting quantum systems against noise coming from the detection chain. However, commercial, cryogenic circulators, now in…
Nonreciprocal circuit elements form an integral part of modern measurement and communication systems. Mathematically they require breaking of time-reversal symmetry, typically achieved using magnetic materials and more recently using the…
A quantum interface between microwave and optical photons is essential for entangling remote superconducting quantum processors. To preserve fragile quantum states, a transducer must operate efficiently while generating less than one photon…
Tailoring the decay rate of structured quantum emitters into their environment opens new avenues for nonlinear quantum optics, collective phenomena, and quantum communications. Here we demonstrate a novel coupling scheme between an…
We have investigated the flux transfer characteristics of a switchable flux transformer comprising a superconducting loop and a DC superconducting quantum interference device (DC-SQUID). This system can be used to couple multiple flux…
We have realized controllable coupling between two three-junction flux qubits by inserting an additional coupler loop between them, containing three Josephson junctions. Two of these are shared with the qubit loops, providing strong…
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…
Non-reciprocal devices, which have different transmission coefficients for propagating waves in opposite directions, are crucial components in many low noise quantum measurements. In most schemes, magneto-optical effects provide the…
Time-division multiplexing of cryogenic signals is a promising approach to reduce space requirements, shorten cooldown times, and increase the number of quantum devices measured per cooldown. We demonstrate time-division multiplexing of…
We introduce a hybrid qubit based on a semiconductor nanowire with an epitaxially grown superconductor layer. Josephson energy of the transmon-like device ("gatemon") is controlled by an electrostatic gate that depletes carriers in a…
A Josephson diode is a non-reciprocal circuit element that supports a larger dissipationless supercurrent in one direction than in the other. In this work, we propose and theoretically study a class of Josephson diodes based on supercurrent…
Fast, high-fidelity measurement is a key ingredient for quantum error correction. Conventional approaches to the measurement of superconducting qubits, involving linear amplification of a microwave probe tone followed by heterodyne…
Josephson tunnel junctions are widely used as nonlinear elements in superconducting circuits such as low noise amplifiers and quantum bits. However, microscopic defects in the oxide tunnel barrier can produce low and high frequency noise…
The reproducibility of qubit parameters is a challenge for scaling up superconducting quantum processors. Signal crosstalk imposes constraints on the frequency separation between neighboring qubits. The frequency uncertainty of transmon…
We propose a scheme of using two fixed frequency resonator couplers to tune the coupling strength between two Xmon qubits. The induced indirect qubit-qubit interactions by two resonators could offset with each other, and the direct coupling…
We report the efficient coupling of a $50\,\Omega$ microwave circuit to a high impedance conductor. We use an impedance transformer consisting of a $\lambda/4$ co-planar resonator whose inner conductor contains an array of superconducting…
We present a practical design and implementation of a broadband sample holder suitable for microwave experiments with superconducting integrated circuits at millikelvin temperatures. Proposed design can be easily integrated in standard…