A device includes: a first chip including a qubit; and a second chip bonded to the first chip, the second chip including a substrate including first and second opposing surfaces, the first surface facing the first chip, wherein the second chip includes a single layer of superconductor material on the first surface of the substrate, the single layer of superconductor material including a first circuit element. The second chip further includes a second layer on the second surface of the substrate, the second layer including a second circuit element. The second chip further includes a through connector that extends from the first surface of the substrate to the second surface of the substrate and electrically connects a portion of the single layer of superconducting material to the second circuit element.

Disclosed are electrochemically tunable metamaterials which are capable of complete reversibility such that the metamaterial itself can physically disappear (out of the active region) and reappear later, in a controllable manner. Some variations provide an electrochemically tunable, solid-state metamaterial-based device comprising a plurality of metamaterial unit cells, wherein each of the metamaterial unit cells comprises: an ion conductor containing mobile metal ions; a first electrode in contact with the ion conductor, wherein the first electrode is contained in a metasurface negative space disposed on the ion conductor; a second electrode in contact with the ion conductor, wherein the second electrode is electrically isolated from the first electrode; and a metal-containing region containing one or more metals, wherein the metal-containing region is contained within a metasurface positive space disposed on the ion conductor.

A NEMS readout system includes a sensor array comprising a plurality of sensors. Each sensor of the plurality of sensors including a resonator with frequency characteristics different from the resonator of each other sensor of the plurality of sensors. A readout signal indicative of a plurality of output signals is collected from the sensor array. Each output signal of the plurality of output signals corresponding to one of the plurality of sensors. An analysis of the plurality of output signals is performed to identify a plurality of resonant frequencies and to detect a frequency shift associated with at least one of the plurality of resonant frequencies.

A device includes: a substrate; a first superconductor layer on the substrate, the first superconductor layer having a first kinetic inductance; and a second superconductor layer on the first superconductor layer, the second superconductor layer having a second kinetic inductance that is lower than the first kinetic inductance, in which the second superconductor layer covers the first superconductor layer such that the second superconductor layer and the first superconductor layer have a same footprint, with the exception of at least a first region where the second superconductor layer is omitted so that the first superconductor layer and the second superconductor layer form a circuit element having a predetermined circuit parameter.

A device includes: a first chip including a qubit; and a second chip bonded to the first chip, the second chip including a substrate including first and second opposing surfaces, the first surface facing the first chip, wherein the second chip includes a single layer of superconductor material on the first surface of the substrate, the single layer of superconductor material including a first circuit element. The second chip further includes a second layer on the second surface of the substrate, the second layer including a second circuit element. The second chip further includes a through connector that extends from the first surface of the substrate to the second surface of the substrate and electrically connects a portion of the single layer of superconducting material to the second circuit element.

A NEMS readout system includes a sensor array comprising a plurality of sensors. Each sensor of the plurality of sensors including a resonator with frequency characteristics different from the resonator of each other sensor of the plurality of sensors. A readout signal indicative of a plurality of output signals is collected from the sensor array. Each output signal of the plurality of output signals corresponding to one of the plurality of sensors. An analysis of the plurality of output signals is performed to identify a plurality of resonant frequencies and to detect a frequency shift associated with at least one of the plurality of resonant frequencies.

A method for manufacturing a superconducting LC-type resonator of the type including at least one high-resistivity substrate on which are printed an inductive meander, a first so-called lower electrode and a second so-called upper electrode arranged opposite the first so as to form together a capacitor connected in parallel with the inductive meander, as well as inductive coupling means dedicated to the resonator, in which a sacrificial aluminium layer is deposited between the first and second electrodes. Also disclosed is the superconducting LC-type resonator thus obtained and the use of such a resonator for detecting the noise of a millimetre photon.

A quantum system includes a qubit array comprising a plurality of qubits. A bus resonator is coupled between at least one pair of qubits in the qubit array. A switch is coupled between the at least one qubit pair of qubits.

Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.

An electrical filter structure for forwarding an electrical signal from a first port, e.g. P1, to a second port, e.g. P2, in a frequency selective manner, wherein the filter is a microwave filter, the electrical filter structure comprising: a plurality of pairs of an open stub and a short-circuited stub coupled electrically in parallel to a transmission line comprising a plurality of transmission line portions at a plurality of respective junctions between adjacent transmission line portions, e.g. Cross junction; and wherein the first port is connected with a first of the junctions having a first pair comprising a first open stub and a first short-circuited stub; wherein the second port is connected with a last of the junctions having a last pair comprising a last open stub and a last short-circuited stub; wherein lengths of the pair of the open stub and the short-circuited stub coupled to a same of the junctions are chosen such that electrical lengths of the open stub and short-circuited stub of the respective pairs are equal within a tolerance of +/−10%.