International Business Machines Corporation

Government of the United States of America, As Represented by the Secretary of Commerce

George Andrew Keefe

Mary Beth Rothwell

James Robert Rozen

Matthias Steffen

Roger Hilsen Koch

David William Abraham

Antonio D Corcoles Gonzalez

Frank Milliken, Jr

Josephine B Chang

Jerry M Chow

Chad Tyler Rigetti

Matthew J Farinelli

Srikanth Srinivasan

Shwetank Kumar

Christian Lavoie

David P DiVincenzo

Guido Burkard

Dongbing Shao

David C Mckay

Firat Solgun

Abhinav Kandala

Aaron Finck

John Blair

Muir Kumph

John Ray Blair

Mary Elizabeth Rothwell

Jiri Stehlik

Chang Chyi Tsuei

David Zajac

David P Pappas

Thomas George McConkey

Xuan Wei

Jiansong Gao

David S Wisbey

Dustin A Hite

Michael R Vissers

Inga Koch, Legal Representative

David DiVincenzo

James R Rozer

Devices and/or computer-implemented methods to facilitate a multipole filter on a quantum device with multiplexing capability and signal separation to mitigate crosstalk are provided. According to an embodiment, a device can comprise an interposer substrate comprising a readout resonator. The device can further comprise a qubit chip substrate comprising a qubit coupled to the readout resonator and to a multipole filter.

Multipole filter on a quantum device with multiplexing and signal separation

One or more systems, devices and/or methods of use provided herein relate to a device that can facilitate reduction of inter-qubit cross talk and/or allow for increased interaction strengths between qubits as compared to existing technologies. A device can comprise a qubit lattice comprising a plurality of repeated and connected unit cells, and the unit cells comprising individual sets of qubits, wherein the unit cells comprise different cross talk groups of qubits having qubit islands connected together by couplers in different orders, and wherein the different cross talk groups are repeated among the unit cells of the qubit lattice. A device can comprise a qubit lattice comprising a plurality of different, interconnected cross talk groups of qubits, wherein the different cross talk groups are repeated within the qubit lattice.

Quantum logic circuit qubit layouts

Systems and techniques that facilitate space-saving coupler arm arrangement for superconducting qubits are provided. In various embodiments, a device can comprise a superconducting qubit. In various aspects, the superconducting qubit can be capacitively coupled to two or more coupler arms. In various instances, a parasitic capacitance between the two or more coupler arms can be within an order of magnitude of a capacitance between the superconducting qubit and at least one of the two or more coupler arms. In various cases, the parasitic capacitance can arise due to a physical proximity between the two or more coupler arms.

Space-saving coupler arm arrangement for superconducting qubits

A device comprises first and second qubits, and a qubit coupler coupled between the first and second qubits. The second qubit comprises first and second modes with the first mode configured to store data. The qubit coupler comprises first and second modes, and operates in a first state or second state. In the first state, the first qubit is exchange coupled to the first mode of the qubit coupler, and the second mode of the second qubit is exchange coupled to the second mode of the qubit coupler, to suppress interaction between the first and second qubits. In the second state, the first qubit and the first mode of the second qubit are exchange coupled to both the first and second modes the qubit coupler, to enable interaction between the first and second qubits for an entanglement gate operation in response to a control signal applied to the qubit coupler.

Multimode coupler to control interaction between quantum bits

A qubit system includes a substrate layer, a qubit circuit suspended above the substrate layer and fine structure disposed between the qubit circuit and the substrate layer.

Suspended superconducting qubits

A coplanar waveguide device includes a coplanar waveguide structure disposed on a substrate, at least one qubit coupled to the coplanar waveguide structure and an add-on chip having a metallized trench, and disposed over the substrate.

Removal of spurious microwave modes via flip-chip crossover

A method for fabricating a chip surface base includes preparing a first substrate, preparing a plurality of vias in the first substrate, depositing metal fillings into the plurality of vias, preparing a second substrate, bonding the first and second substrates and exposing the metal fillings. A method for fabricating a chip surface base includes preparing a first and second substrate, depositing a metal on at least one of the first and second substrates, bonding the first and second substrates, preparing a plurality of vias in the first substrate, depositing metal fillings into the plurality of vias and exposing the metal fillings. A chip surface base device includes a first substrate, a second substrate, a metal layer disposed between the first and second substrates and a plurality vias disposed on the first substrate.

Chip mode isolation and cross-talk reduction through buried metal layers and through-vias

Method of fabricating a coplanar waveguide device including removal of spurious microwave modes via flip-chip crossover

A method for fabricating a chip surface base includes preparing a first substrate, preparing a plurality of vias in the first substrate, depositing metal fillings into the plurality of vias, preparing a second substrate, bonding the first and second substrates and exposing the metal fillings. A method for fabricating a chip surface base includes preparing a first and second substrate, depositing a metal on at least one of the first and second substrates, bonding the first and second substrates, preparing a plurality of vias in the first substrate, depositing metal fillings into the plurality of vias and exposing the metal fillings. A chip surface base device includes a first substrate, a second substrate, a metal layer disposed between the first and second substrates and a plurality of vias disposed on the first substrate.

Low-loss superconducting devices and methods for fabricating low loss superconducting devices. For example, superconducting devices, such as superconducting resonator devices, are formed with a (200)-oriented texture titanium nitride (TiN) layer to provide high Q, low loss resonator structures particularly suitable for application to radio-frequency (RF) and/or microwave superconducting resonators, such as coplanar waveguide superconducting resonators. In one aspect, a method of forming a superconducting device includes forming a silicon nitride (SiN) seed layer on a substrate, and forming a (200)-oriented texture titanium nitride (TiN) layer on the SiN seed layer.

Low-loss superconducting devices

An apparatus and method for manufacturing a superconducting low-pass filter for quantum computing devices. The apparatus includes a plurality of containers and input and output ports connected to opposite ends of the apparatus. A plurality of coils of superconducting wire are wound using a mandrel. An adhesive is applied to the coils for maintaining a wound state. Each of the coils are positioned in each of the containers and electrically connected to each other with at least one coil being connected to the input port and at least one coil being connected to the output port. The coils are released or expanded from their wound state using an adhesive solvent. The containers are then filled with a conductive polymer and the containers are closed with one or more covers.

Method of manufacturing superconducting low pass filter for quantum computing

A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Microwave readout for flux-biased qubits

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Cortlandt Manor, NY, United States of America

George Andrew Keefe