A method for adjusting a resonance frequency of a qubit in a quantum mechanical device includes providing a substrate having a frontside and a backside, the frontside having at least one qubit formed thereon, the at least one qubit comprising capacitor pads; and removing substrate material from the backside of the substrate at an area opposite the at least one qubit to alter a capacitance around the at least one qubit so as to adjust a resonance frequency of the at least one qubit.

A flux-biasing device includes a set of magnetic flux generating members. A first magnetic flux generating member is configured to magnetically interact with a first qubit from a set of qubits of a quantum processor such that a first magnetic flux of the first member causes a first change in a first resonance frequency of the first qubit by a first frequency shift value. Each non-corresponding magnetic flux generating member of the set is well separated from qubits corresponding to other magnetic flux generating members of the set such that qubits corresponding to other members exhibit less than a threshold value of resonance frequency shift as a result of a magnetic flux of a non-corresponding member.

A method for bonding two superconducting integrated circuits (“chips”), such that the bonds electrically interconnect the chips. A plurality of indium-coated metallic posts may be deposited on each chip. The indium bumps are aligned and compressed with moderate pressure at a temperature at which the indium is deformable but not molten, forming fully superconducting connections between the two chips when the indium is cooled down to the superconducting state. An anti-diffusion layer may be applied below the indium bumps to block reaction with underlying layers. The method is scalable to a large number of small contacts on the wafer scale, and may be used to manufacture a multi-chip module comprising a plurality of chips on a common carrier. Superconducting classical and quantum computers and superconducting sensor arrays may be packaged.

A method of producing a quantum circuit includes forming a mask on a substrate to cover a first portion of the substrate, implanting a second portion of the substrate with ions, and removing the mask, thereby providing a nanowire. The method further includes forming a first lead and a second lead, the first lead and the second lead each partially overlapping the nanowire. In operation, a portion of the nanowire between the first and second leads forms a quantum dot, thereby providing a quantum dot Josephson junction. The method further includes forming a third lead and a fourth lead, one of the third and fourth leads partially overlapping the nanowire, wherein the third lead is separated from the fourth lead by a dielectric layer, thereby providing a Dolan bridge Josephson junction. The nanowire is configured to connect the quantum dot Josephson junction and the Dolan bridge Josephson junction in series.

Techniques for a quantum device with modular quantum building blocks are provided. In one embodiment, a device is provided that comprises a substrate that is coupled with a plurality of qubit pockets, where at least one qubit pocket of the plurality of qubit pockets is coupled with a qubit. In one implementation, the device can further comprise a plurality of connectors coupled to the substrate and positioned around at least a portion of the substrate, where the plurality of connectors comprising a connecting element. In one or more implementations, the device can further comprise a plurality of transmission lines formed on the substrate and connect at least one connector of the plurality of connectors to at least one qubit pocket of the plurality of qubit pockets.

A flux-biasing device includes a set of magnetic flux generating members. A first magnetic flux generating member is configured to magnetically interact with a first qubit from a set of qubits of a quantum processor such that a first magnetic flux of the first member causes a first change in a first resonance frequency of the first qubit by a first frequency shift value. Each non-corresponding magnetic flux generating member of the set is well separated from qubits corresponding to other magnetic flux generating members of the set such that qubits corresponding to other members exhibit less than a threshold value of resonance frequency shift as a result of a magnetic flux of a non-corresponding member.

A magnetic field measuring apparatus that includes a first board having a plurality of first connecting parts, at least one second board connected to the plurality of first connection parts, and a power supply unit supplying power to the first board and the at least one second board so as to measure a magnetic field includes at least one first voltage regulator disposed on the first board to generate a first voltage using power from the power supply unit; and at least one second voltage regulator disposed on any one of the at least one second board to generate a second voltage using the first voltage.

An aspect includes one or more board layers. A first chip cavity is formed within the one or more board layers, wherein a first Josephson amplifier or Josephson mixer is disposed within the first chip cavity. The first Josephson amplifier or Josephson mixer comprises at least one port, each port connected to at least one connector disposed on at least one of the one or more board layers, wherein at least one of the one or more board layers comprises a circuit trace formed on the at least one of the one or more board layers.

A quantum computing device is formed using a first chip and a second chip, the first chip having a first substrate, a first set of pads, and a set of Josephson junctions disposed on the first substrate. The second chip has a second substrate, a second set of pads disposed on the second substrate opposite the first set of pads, and a second layer formed on a subset of the second set of pads. The second layer is configured to bond the first chip and the second chip. The subset of the second set of pads corresponds to a subset of the set of Josephson junctions selected to avoid frequency collision between qubits in a set of qubits. A qubit is formed using a Josephson junction from the subset of Josephson junctions and another Josephson junction not in the subset being rendered unusable for forming qubits.

Techniques for a quantum device with modular quantum building blocks are provided. In one embodiment, a device is provided that comprises a substrate that is coupled with a plurality of qubit pockets, where at least one qubit pocket of the plurality of qubit pockets is coupled with a qubit. In one implementation, the device can further comprise a plurality of connectors coupled to the substrate and positioned around at least a portion of the substrate, where the plurality of connectors comprising a connecting element. In one or more implementations, the device can further comprise a plurality of transmission lines formed on the substrate and connect at least one connector of the plurality of connectors to at least one qubit pocket of the plurality of qubit pockets.