International Business Machines Corporation

Egypt Nanotechnology Center

Nikolaj Moll

Thomas E Morf

Thomas Pflueger

Matthias Fertig

Daniel Josef Egger

Stefan Filipp

Gian R Von Salis

Rainer Friedbert Mahrt

Marc Ganzhorn

Jens Hofrichter

Jonas R Weiss

Folkert Horst

Andreas Fuhrer

Marco Pistoia

Jay Michael Gambetta

Bruno Michel

Richard Chen

Stephen Peter Wood

Shaohan Hu

Rudy Raymond Harry Putra

Antonio Mezzacapo

Peng Liu

Julia Elizabeth Rice

Ivano Tavernelli

Panagiotis Barkoutsos

Thilo H C Stoeferle

Rami Ghannam

Thilo Hermann Curt Stöferle

Sophie Schoenenberger

Kristian Gotthold Baumann

A quantum processing comprises n fixed-frequency quantum circuits of distinct frequencies, where n&#x2265;3. The device further comprises a frequency-tunable coupler, designed in such a manner that its frequency can be concomitantly modulated at m frequencies, where m&#x2265;2, and wherein said m frequencies correspond, each, to a difference of energy between a respective pair of quantum states spanned by the quantum circuits. The quantum circuits are, each, coupled to the tunable coupler. The method may rely on modulating the frequency of the tunable coupler concomitantly at said m frequencies. This, for example, is done so as to drive m energy transitions between connected pairs of states spanned by the quantum circuits and achieve an entangled state of the quantum circuits as a superposition of l states spanned by the quantum circuits, l&#x2265;m.

Multi-qubit entangling gate using a frequency-modulated tunable coupler

A method of operating a quantum information processing apparatus is provided. This apparatus includes a structure of coupled qubits, where N&#x2265;3, wherein the structure further includes coupling elements. The coupling elements couple pairs of N qubits, wherein, at least, a portion of the qubits are connected by a respective one of the coupling elements, whereby the two qubits of each said pair are connected by a respective coupling element. A method comprises identifying a path of M qubits in the structure of coupled qubits, wherein the path extends from a first qubit to a last qubit of the N qubits. The identified path consists of M qubits and M&#x2212;1 coupling elements alternating along said path, where 2&#x3c;M&#x2264;N. A single-cycle operation is performed, wherein all pairs of two successive qubits in the identified path are concomitantly subjected to exchange-type interactions of distinct strengths.

Single-cycle operations using controllably mediated exchange-type interactions between qubits

Systems, computer-implemented methods, and computer program products to facilitate quantum domain computation of classical domain specifications are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise an input transformation component that can be adapted to receive one or more types of domain-specific input data corresponding to at least one of a plurality of domains. The input transformation component can transform the one or more types of domain-specific input data to quantum-based input data. The computer executable components can further comprise a circuit generator component that, based on the quantum-based input data, can generate a quantum circuit.

Quantum computations of classical specifications

Techniques relate to operating a quantum processing device is provided. The device includes at least two fixed-frequency quantum circuits coupled to a frequency-tunable coupler. The frequency of the coupler can be modulated so as to drive at least two selectively addressable energy transitions in the quantum processing device. The method includes modulating the frequency of the coupler so as to drive two first-order energy transitions. This is done so as to transfer (at least partly) an excitation of one of the quantum circuits to at least another one of the quantum circuits, via the tunable coupler. Related quantum processing devices are also provided.

Fast quantum gates with first-order transitions via frequency-modulated tunable coupling element

A method for operating a quantum processing device is provided including at least two quantum circuits coupled to a tunable coupler, wherein the quantum circuits are subject to cross-talk, the method including: applying a primary signal to the quantum circuits so as to drive one or more energy transitions between states spanned by the quantum circuits; and applying a compensation signal to the tunable coupler, the compensation signal designed so as to shift at least one state spanned by the quantum circuits, in energy, to compensate for cross-talk between the quantum circuits. Related quantum processing devices and chips are also provided.

Cross-talk compensation in quantum processing devices

A photovoltaic cell includes an absorbing layer configured to generate electron-hole pairs from incident photons of incoming light; and a first grating layer arranged at a first surface of the absorbing layer which is opposite to a second surface of the absorbing layer from which light is incident, wherein the first grating layer includes at least one grating extending along the first surface, wherein the at least one grating has grating structures which are dimensioned to provide a reflectivity for light incident through the absorbing layer back into the absorbing layer.

Light-reflecting grating structure for photovoltaic devices

The photo detector () comprises a photo transistor (). The photo transistor has a light sensitive region () for controlling the transistor action of the photo transistor. The photo detector further comprises a dielectric layer (). The dielectric layer is in contact with the photo transistor. The photo detector further comprises a grating pattern () in contact with the dielectric layer. The grating layer and the dielectric layer are adapted for focusing electromagnetic radiation in the light sensitive region.

Photo detector and integrated circuit

An electromagnetic wave isolator () comprising a body () having e.g. an elliptical disk or ring shape such as to define two circular directions (D, D) of propagation. The body is further augmented by one or more feature () lowering the symmetry of the isolator such that wave propagation is supported substantially more in one (D) of the directions than in the opposite direction (D). An integrated optics device includes two electromagnetic wave isolators.

Electromagnetic wave isolator and integrated optics device

A high quality factor optical resonator structure includes a substrate, a center disc formed on the substrate, and a plurality of concentric grating rings surrounding the center disc. The concentric rings are spaced apart from the center disc and from one another by regions of lower index of refraction material with respect thereto, and wherein spacing between the grating rings and the center disc is non-periodic such that a magnitude of a displacement distance of a given grating ring with respect to a &#x3bb;/4 Bragg reflector geometry is largest for a first of the grating rings immediately adjacent the center disk and decreases in a radially outward direction.

Radial Bragg ring resonator structure with high quality factor

A method and apparatus for designing a device to operate in a coupling mode, a detection mode, or a reflection mode for incident light. The incident light has a wavelength &#x3bb; and is incident upon a semiconductor structure of the device at an angle of incidence (&#x3b8;). A voltage (V) is applied to the device. Each mode may be designed for an ON state and/or OFF state. For the coupling mode and detection mode, the ON state and OFF state is characterized by high and low absorption of the incident light, respectively, by the semiconductor structure in conjunction with the applied voltage V and angle of incidence &#x3b8;. For the reflection mode, the OFF state and ON states is characterized by a shift in the optical path length of &#x3bb;/2 and about zero, respectively, in conjunction with the applied voltage V and angle of incidence &#x3b8;.

Computer implemented design of device for electro-optical modulation of light incident upon device

A method of coupling a light beam into a waveguide. The method includes applying the light beam onto a grating portion at non-zero degree angle with respect to a plane of the grating portion, coupling the light beam into the waveguide using the grating portion and converting a spot-size of the light beam to correspond with a size of the waveguide using the grating portion.

Optical coupling method

A multi-junction opto-electronic device including a stack of wavelength selective absorption layers is proposed. The absorption layers include each a first layer with a grating of a specific pitch defining the wavelength of the incident light to be absorbed within a subjacent second electrically active layer itself on a third electrically inactive layer. The second electrically active layer within the different absorption layers is in electrical connection with lateral contacts to extract the electrical charge carriers generated by the absorbed incident light within the active layer. The grating within the first layer of the absorption layers is defined by periodic stripes of specific width depending on the wavelength to be absorbed by the respective absorption layers. The period of the stripes alignment is defined by the pitch of the grating. Advantageously, ordinary silicon technology can be used.

Using 3d integrated diffractive gratings in solar cells

Various embodiments of an optical switch device are provided. In one embodiment, the optical switch device includes a substrate. A photonic crystal, having a dielectric material, is applied on the substrate. An optical gain layer, having an optical gain material, is disposed above the photonic crystal. The photonic crystal is formed with a second-order distributed feedback structure to emit laser light perpendicular to a plane of the photonic crystal and a first-order distributed feedback structure adapted for reflecting light in the plane of the photonic crystal back into the second-order distributed feedback structure. The first-order distributed feedback structure at least one of fully surrounds the second-order distributed feedback structure and is arranged on two opposing edges of the second-order distributed feedback structure.

Optical wavelength switch

A method and apparatus for designing a device to operate in a coupling mode, a detection mode, or a reflection mode for incident light. The incident light has a wavelength &#x3bb; and is incident upon a semiconductor structure of the device at an angle of incidence (&#x3b8;). A voltage (V) is applied to the device. Each mode may be designed for an ON state and/or OFF state. For the coupling mode and detection mode, the ON state and OFF state is characterized by high and low absorption of the incident light, respectively, by the semiconductor structure in conjunction with the applied voltage V and angle of incidence &#x3b8;. For the reflection mode, the OFF state and ON states is characterized by a shift in the optical path length of &#x3bb;/2 and about zero, respectively, in conjunction with the applied voltage V and angle of incidences &#x3b8;.

Growing community of inventors

Zurich, Switzerland

Nikolaj Moll