Yale University

Shyam Shankar

Michel Devoret

Luigi Frunzio

Katrina Sliwa

Anirudh Narla

Michael Hatridge

Robert J Schoelkopf, Iii

Nicholas Frattini

Steven M Girvin

Shruti Puri

Jayameenakshi Venkatraman

Xu Xiao

Shantanu Mundhada

W Clarke Smith

Volodymyr Sivak

Uri Vool

László J Szöcs

Mazyar Mirrahimi

Lucas Verney

Robert J Schoelkopf Iii

Robert J Schoelkopf

Laszlo J Szocs

Robert J Iii Schoelkopf

Parametrically pumped four-wave mixing is a key building block for many developments in the field of superconducting quantum information processing. However, undesired frequency shifts such as Kerr, cross-Ken and Stark shifts inherent with four-wave mixing, lead to difficulties in tuning up the desired parametric processes and, for certain applications, severely limit the fidelities of the resulting operations. Some embodiments include a Josephson four-wave mixing device consisting of a SQUID transmon coupled to a half-flux biased SNAIL transmon, a.k.a. capacitively shunted flux qubit. When the two transmon have matching frequencies, an interference effect cancels the negative Kerr of the SQUID transmon with the positive Kerr of the SNAIL transmon while preserving parametric four-wave mixing capabilities.

Josephson nonlinear circuit

A superconducting device includes two nodes and a Josephson junction coupled between the two nodes, wherein the Josephson junction is characterized by a superconducting phase difference, &#x3c6;, wherein the superconducting device has a potential that varies as a function of the superconducting phase difference, &#x3c6;, and has a single potential well. The potential has a non-zero cubic term and quartic term is zero. The Josephson junction may be a single small Josephson junction. The superconducting device may include a superconducting ring connected between the two nodes. The superconducting ring may include a first ring portion with a plurality of large Josephson junctions connected in series. The superconducting ring may also include a second ring portion that includes the single small Josephson junction in parallel with the plurality of large Josephson junctions between the two nodes.

Superconducting nonlinear asymmetric inductive element and related systems and methods

A wireless Josephson-junction-based amplifier is described that provides improved tunability and increased control over both a quality factor Q and participation ratio p of the amplifier. The device may be fabricated on a chip and mounted in a waveguide. No wire bonding between the amplifier and coaxial cables or a printed circuit board is needed. At least one antenna on the chip may be used to couple energy between the waveguide and wireless JBA. The amplifier is capable of gains greater than 25 dB.

Wireless Josephson bifurcation amplifier

Techniques for modifying the Josephson potential of a transmon qubit by shunting the transmon with an inductance are described. The inclusion of this inductance may increase the confined potential of the qubit system compared with the conventional transmon, which may lead to a transmon qubit that is stable at much higher drive energies. The inductive shunt may serve the purpose of blocking some or all phase-slips between the electrodes of the qubit. As a result, the inductively shunted transmon may offer an advantage over conventional devices when used for applications involving high energy drives, whilst offering few to no drawbacks in comparison to conventional devices when used at lower drive energies.

Inductively-shunted transmon qubit for superconducting circuits

A wireless Josephson-junction-based parametric converter is described. The converter may be formed on a substrate with antennas that pump are configured to wirelessly receive pump, signal and idler frequencies and couple the received frequencies to the converter's circuitry. Capacitors may also be fabricated on the same substrate and sized to tune operation of the converter to desired frequencies. The converter may be coupled directly to microwave waveguides, and may be tuned to different signal frequencies by applying magnetic flux to the converter circuitry.

Wireless Josephson parametric converter

According to some aspects, a circuit is provided comprising a plurality of Josephson junctions arranged in series in a loop, at least one magnetic element producing magnetic flux through the loop, a plurality of superconducting resonators, each resonator coupled to the loop between a different neighboring pair of Josephson junctions of the plurality of Josephson junctions, a plurality of ports, each port coupled to at least one of the plurality of resonators at ends of the resonators opposite to ends at which the resonators are coupled to the loop, and at least one controller configured to provide input energy to each of the plurality of ports that causes the circuit to function as a circulator between the plurality of ports.

Josephson junction-based circulators and related systems and methods

According to some aspects, a quantum circuit is provided including a plurality of non-linear circuit elements coupled together in series and in parallel, such that at least two of the circuit elements are coupled together in series and at least two of the circuit elements are coupled together in parallel, wherein the quantum circuit is configured to act as an amplifier.

Techniques for producing quantum amplifiers and related systems and methods

Growing community of inventors

New Haven, CT, United States of America

Shyam Shankar