Iqm Finland Oy

Teknologian Tutkimuskeskus Vtt Oy

Juha Hassel

Mikko Möttönen

Pasi Lähteenmäki

Andrey Timofeev

Tianyi Li

Kok Wai Chan

Johannes Heinsoo

Kuan Yen Tan

Arttu Luukanen

Jani Tuorila

Panu Helistö

Wei Liu

Visa Vesterinen

Caspar Ockeloen-Korppi

Jan Goetz

Manjunath Ramachandrappa Venkatesh

Máté Jenei

Leif Grönberg

Hannu Sipola

Eric Hyyppä

Joonas Govenius

Tuomas Ollikainen

Vasilii Sevriuk

Jari Penttilä

Jukka Räbinä

Panu HelistÖ

Leif GRÖNBERG

A quantum computing system, a method, a computer program, and an arrangement for selectively shifting qubit resonance frequencies are disclosed herein. According to an embodiment, an arrangement for selectively shifting qubit resonance frequencies in a quantum computing system comprises a plurality of qubits including at least a first qubit and a second qubit, and a plurality of coupling control resonators including at least a first coupling control resonator and a second coupling control resonator. The arrangement also includes a coupling control signal line. The first coupling control resonator may be configured to shift the resonance frequency of the first qubit when the coupling control signal includes a frequency component in the resonance frequency band of the first coupling control resonator.

Selective frequency shifting of qubits

A microwave power source comprises a Josephson junction or junction array and a resonant tank circuit coupled thereto and configured to resonate at one or more frequencies of Josephson oscillation. An output coupler is coupled to said resonant tank circuit for outputting microwave power from said resonant tank circuit. A bias circuit is coupled to the Josephson junction and configured to produce a bias voltage across the Josephson junction. Said bias circuit comprises a current path of variable resistance between a bias input of the microwave power source and a reference potential.

Microwave power source, and a method for generating microwave signals

A vector signal generator is capable of operating on microwave frequencies. It comprises a microwave resonator, an output for coupling microwave photons out of said microwave resonator, and a Josephson junction or junction array coupled to the microwave resonator for emitting microwave signals into the microwave resonator. A biasing circuit is provided for applying a bias to the Josephson junction or junction array. A tunable attenuator is coupled to said microwave resonator.

Vector signal generator operating on microwave frequencies, and method for generating time-controlled vector signals on microwave frequencies

A sample cell is provided for holding a sample to be placed in a cryogenically cooled environment. The sample cell comprises an airtight, openable and closable enclosure. Within said enclosure is a sample base for receiving the sample. A refrigerator attachment is provided for attaching the sample cell to a refrigerated body of a cryogenically cooled environment. The sample cell comprises a thermal connection between the sample base and the refrigerator attachment. One or more airtight connectors are provided for establishing electric connections between inside and outside of said enclosure.

Sample cell for handling and measuring sensitive samples in low temperature conditions

A cryogenic integrated circuit or integrated module includes a travelling wave parametric amplifier or a Josephson parametric amplifier. The cryogenic integrated circuit or integrated module also includes an oscillator, a signal input, a biasing input, and a signal output. The oscillator is connected to an input of the amplifier and is configured to produce an oscillating drive signal. The signal input couples input signals into the amplifier. The biasing input couples biasing signals into the oscillator. The signal output conveys output signals from the amplifier out of the cryogenic integrated circuit or integrated module.

Cryogenic integrated circuit, integrated module, and arrangement for producing and detecting excitation and readout signals of qubits

The disclosure relates to a quantum detector configured to receive a microwave signal from a microwave source. The quantum detector comprises a main element formed by a main Josephson junction and a Josephson transmission line which is coupled to the main element for outputting a measurement signal. The Josephson transmission line comprises at least a first set of JTL elements and a second set of JTL elements. The capacitively shunted Josephson junction in each JTL element in the first set is weakly damped, and the JTL element in the second set are more strongly damped than the JTL elements in the first set.

Self-resetting single flux-quantum microwave photodetector

A superconducting circuit comprises a first and second magnetic-flux-tunable elements. Each of these has a respective flux-sensitive part. First and second current-driven superconductive on-chip flux bias lines are provided. Each of these passes adjacent to the flux-sensitive part of the respective magnetic-flux-tunable element. A first plurality of superconductive stray current paths exists adjacent to the first magnetic-flux-tunable element. A second plurality of superconductive stray current paths exist adjacent to the second magnetic-flux-tunable element. The superconductive stray current paths distribute stray currents originating from the flux line of the other magnetic-flux-tunable element into a respective plurality of stray currents around the respective magnetic-flux-tunable element. This way the stray currents are kept from changing the electric characteristics of the respective magnetic-flux-tunable element.

Superconducting circuit with magnetic-flux-tunable elements, and methods for minimizing flux crosstalk between magnetic flux-tunable elements in superconducting circuits

A quantum processing unit is disclosed. The quantum processing unit includes at least one superconducting qubit that is based on phase-biased linear and non-linear inductive-energy elements. A superconducting phase difference across the linear and non-linear inductive-energy elements is biased, for example, by an external magnetic field, such that quadratic potential energy terms of the linear and non-linear inductive-energy elements are cancelled at least partly. In a preferred embodiment, such cancellation is at least 30%. The partial cancellation of the quadratic potential energy terms makes it possible to implement a high-coherence high-anharmonicity superconducting qubit design.

Quantum processing unit comprising one or more superconducting qubits based on phase-biased linear and non-linear inductive-energy elements

According to an example aspect of the present invention, there is provided a travelling wave parametric amplifier comprising a waveguide transmission line comprising therein at least ten Josephson elements, wherein each of the at least ten Josephson element comprises a loop, with exactly one Josephson junction of first size on one half of the loop and at least two Josephson junctions of a second size on a second half of the loop, the second size being larger than the first size, a flux bias line configured to generate a magnetic flux threading each of the at least one loop, and a set of resistors coupled with the flux bias line.

Josephson traveling wave parametric amplifier

A solution for reading detector arrays is disclosed. The solution comprises generating () an excitation signal, varying () the frequency of the excitation signal in time, supplying () the excitation signal to a detector array comprising a set of thermal detectors. The number of detectors corresponds to the frequencies of the excitation signal. In the solution, the signal is demodulated () at the output of the detector array and time-multiplexed base band signal is obtained. An analogue to digital conversion is performed () to the time-multiplexed base band signal and the base band signal is demultiplexed () to obtain a set of detector signals.

Method and apparatus for reading detector arrays

A superconducting thermal detector (bolometer) of THz (sub-millimeter) wave radiation based on sensing the change in the amplitude or phase of a resonator circuit, consisting of a capacitor (Csh) and a superconducting temperature dependent inductor where the said inductor is thermally isolated from the heat bath (chip substrate) by micro-suspensions. The bolometer design includes a thin film inductor located on the membrane, a single or/and multi-layered thin film capacitor, and a thin film absorber of incoming radiation. The bolometer design can also include a lithographic antenna with antenna termination and/or a back reflector beneath the membrane for optimal wavelength detection by the resonance circuit. The superconducting thermal detector (bolometer) and arrays of these detectors operate in a temperature range from 1 Kelvin to 10 Kelvin.

Growing community of inventors

Espoo, Finland

Juha Hassel