Abstract: Topological qubits are provided in a quantum spin liquid. In various embodiments, a device is provided comprising a two-dimensional array of particles, each particle disposed at a vertex of a ruby lattice having a parameter ? greater than 1 2 ; each particle having a first state and an excited state; each particle that belongs to at least three unit cells of the ruby lattice having a blockade radius, when in the excited state, sufficient to blockade each of at least six nearest neighboring particles in the ruby lattice from transitioning from its first state to its excited state, and wherein the array has at least one outer edge configured to be in a first boundary condition.

Abstract: A device, comprising at least one monochromatic light source configured to generate a first optical trap; an ensemble of particles disposed in the first optical trap, each particle of the ensemble of particles being excitable to a first Rydberg state and a second Rydberg state, the second Rydberg state having a blockade radius, each particle of the ensemble of particles being within the blockade radius of each other and within the blockade radius of an atomic qubit, the atomic qubit being a particle that is excitable to the second Rydberg state, the ensemble of particles having a first transmissivity at a first wavelength when neither any particle of the ensemble of particles nor the atomic qubit is in the second Rydberg state, the ensemble of particles having a second transmissivity at the first wavelength when the atomic qubit is in the second Rydberg state, the second transmissivity being lower than the first transmissivity; and a second monochromatic light source configured to drive each particle of the e

Abstract: Systems and methods relate to arranging atoms into 1D and/or 2D arrays; exciting the atoms into Rydberg states and evolving the array of atoms, for example, using laser manipulation techniques and high-fidelity laser systems described herein; and observing the resulting final state. In addition, refinements can be made, such as providing high fidelity and coherent control of the assembled array of atoms. Exemplary problems can be solved using the systems and methods for arrangement and control of atoms.

Abstract: Systems and methods relate to arranging atoms into 1D and/or 2D arrays; exciting the atoms into Rydberg states and evolving the array of atoms, for example, using laser manipulation techniques and high-fidelity laser systems described herein; and observing the resulting final state. In addition, refinements can be made, such as providing high fidelity and coherent control of the assembled array of atoms. Exemplary problems can be solved using the systems and methods for arrangement and control of atoms.

Abstract: Systems and methods relate to arranging atoms into 1D and/or 2D arrays; exciting the atoms into Rydberg states and evolving the array of atoms, for example, using laser manipulation techniques and high-fidelity laser systems described herein; and observing the resulting final state. In addition, refinements can be made, such as providing high fidelity and coherent control of the assembled array of atoms. Exemplary problems can be solved using the systems and methods for arrangement and control of atoms.

Abstract: Systems and methods relate to arranging atoms into 1D and/or 2D arrays; exciting the atoms into Rydberg states and evolving the array of atoms, for example, using laser manipulation techniques and high-fidelity laser systems described herein; and observing the resulting final state. In addition, refinements can be made, such as providing high fidelity and coherent control of the assembled array of atoms. Exemplary problems can be solved using the systems and methods for arrangement and control of atoms.

Abstract: An all-to-all coupled, high-fidelity, error-correctable quantum computer can scale to hundreds of qubits within a single cavity of moderate cooperativity with existing neutral atom technology. This quantum processor can enact teleported gates among any pair of qubits using a local Rydberg interaction between each qubit and a separate network of atoms that distribute entanglement via a cavity mode. Small atomic ensembles at network nodes allow for ultrafast, nondestructive readout with high fidelity by substantially shifting the resonance of even a poor-quality cavity. Fast readout enables near-deterministic entanglement distribution among network atoms despite cavity losses as well as syndrome measurements of qubit atoms for error correction.

Abstract: A quantum computer uses interactions between atomic ensembles mediated by an optical cavity mode to perform quantum computations and simulations. Using the cavity mode as a bus enables all-to-all coupling and execution of non-local gates between any pair of qubits. Encoding logical qubits as collective excitations in ensembles of atoms enhances the coupling to the cavity mode and reduces the experimental difficulty of initial trap loading. By using dark-state transfers via the cavity mode to enact gates between pairs of qubits, the gates become insensitive to the number of atoms within each collective excitation, making it possible to prepare an array of qubits through Poissonian loading without feedback.

Abstract: Systems and methods relate to arranging atoms into 1D and/or 2D arrays; exciting the atoms into Rydberg states and evolving the array of atoms, for example, using laser manipulation techniques and high-fidelity laser systems described herein; and observing the resulting final state. In addition, refinements can be made, such as providing high fidelity and coherent control of the assembled array of atoms. Exemplary problems can be solved using the systems and methods for arrangement and control of atoms.

Abstract: An optical and electronic feedback system can be used to significantly narrow the linewidth of distributed Bragg reflector lasers (DBRs) by reducing the high-frequency noise in the laser spectrum. An optical feedback path reduces the high-frequency noise of the laser. An electric-optic modulator placed inside of this feedback path applies electronic feedback with a very large bandwidth, allowing for robust and stable locking to a reference cavity. In addition, the servo-electronic component greatly increases the long-term stability of the laser locking to an external reference cavity, allowing for low noise, long-term operation of the laser. Specifically, it suppresses the frequency noise spectral density and narrows the total linewidth from a free-running value of 100 kHz to 30 Hz. The resulting modified DBR laser is both precise and stable and has applications in optical clocks, quantum information science, and precision metrology.

Abstract: Described are a method and a system for producing porous iron by means of a direct reduction process. In said method and system, a reducing gas is introduced into a DRI reduction device, and the direct reduction process is carried out therein. Coke oven gas and/or natural gas is/are reformed by adding gas, which contains steam and carbon dioxide and which is top gas from a DRI reduction device, and oxygen in a COG reformer so as to obtain reducing gas.

Abstract: The invention relates to a method and apparatus for cooling multilevel entities such as atoms, ions or molecules as well as entities with no apparent internal structure. Cooling is achieved by coherent scattering, where the frequency of the emitted radiation exceeds the frequency of the illumination radiation. Such coherent scattering is achieved by placing the entities in a resonator containing in which the cavity length and mirror coating are selected to support a resonant radiation. The entities are illuminated with an illumination radiation whose energy is lower than that of the resonant radiation supported by the resonator by a certain detuning energy selected such that coherent scattering of resonant radiation from the entities at a higher frequency than that of the illumination radiation is promoted by the resonator. As a result of the coherent scattering energy is carried away from the entities and they are cooled.

Abstract: The invention relates to a method and apparatus for cooling multilevel entities such as atoms, ions or molecules as well as entities with no apparent internal structure. Cooling is achieved by coherent scattering, where the frequency of the emitted radiation exceeds the frequency of the illumination radiation. Such coherent scattering is achieved by placing the entities in a resonator containing in which the cavity length and mirror coating are selected to support a resonant radiation. The entities are illuminated with an illumination radiation whose energy is lower than that of the resonant radiation supported by the resonator by a certain detuning energy selected such that coherent scattering of resonant radiation from the entities at a higher frequency than that of the illumination radiation is promoted by the resonator. As a result of the coherent scattering energy is carried away from the entities and they are cooled.

Abstract: A process for producing pig iron from iron ores involves the iron ores traveling from the top downwards through a reduction unit via a succession of oblique trays which are staggered in a cascade-like manner. A hot reduction gas containing carbon monoxide and hydrogen flows from the bottom of the reduction unit upwards. A reduction product is drawn off at the bottom end of the reduction unit and is fed to a unit for further treatment thereof. A reduction gas is generated in a gas generator by partial oxidation of carbon carriers or by cracking of natural gas or petroleum. Iron ores having at least a high proportion of dust-like and/or fine granular iron ores are sorted into fractions according to grain size and introduced into the reduction unit in such a way that the course fraction of the iron ore is introduced into the top section of the system and the fine fraction of the iron ore is introduced into the middle zone or into the middle and bottom zones of the system.