Abstract: This invention concerns a quantum device, suitable for quantum computing, based on dopant atoms located in a solid semiconductor or insulator substrate. In further aspects the device is scaled up. The invention also concerns methods of reading out from the devices, initializing them, using them to perform logic operations and making them.

Abstract: This invention concerns an electronic device for the control and readout of the electron or hole spin of a single dopant in silicon. The device comprises a silicon substrate in which there are one or more ohmic contact regions. An insulating region on top of the substrate. First and second barrier gates spaced apart to isolate a small region of charges to form an island of a Single Electron Transistor (SET). A third gate over-lying both the first and second barrier gates, but insulated from them, the third gate being able to generate a gate-induced charge layer (GICL) in the ESR line substrate beneath it. A fourth gate in close proximity to a single dopant donor gate atom, the dopant atom being encapsulated in the substrate outside the region of the GICL but close enough to allow spin-dependent charge tunnelling between the dopant atom and the SET island under the control of gate potentials, mainly the fourth gate.

Abstract: This invention concerns interfacing to electronic circuits or systems operating at low temperature or ultra-low temperature using complementary metal-oxide semiconductor (CMOS) technology. Low temperature in this case refers to cryogenic temperatures in particular, but not exclusively, to the 4.2 K region. Ultra-low temperatures here refers to the sub-1 K range, usually accessed using dilution refrigerator systems. The electronic circuits comprise a controller (for writing and manipulation), an observer (for readout and measurement) circuits, or both, fabricated from ultra-thin silicon-on-insulator (SOI) CMOS technology.

Abstract: This invention concerns a quantum device, suitable for quantum computing, based on dopant atoms located in a solid semiconductor or insulator substrate. In further aspects the device is scaled up. The invention also concerns methods of reading out from the devices, initializing them, using them to perform logic operations and making them.

Abstract: A silicon integrated circuit device comprising a near intrinsic silicon substrate in which there are one or more ohmic contact regions. An insulating layer lies above the substrate, and on top of the insulating layer is a lower layer of one or more aluminium gates. The surface of each of the lower gates is oxidised to insulate them from an upper aluminium gate that extends over the lower gates.

Abstract: Ionisation of one of a pair of dopant atoms in a substrate creates a double well potential, and a charge qubit is realised by the location of one or more electrons or holes within this potential. The dopant atoms may comprise phosphorous atoms, located in a silicon substrate. A solid state quantum computer may be formed using a plurality of pairs of dopant atoms, corresponding gate electrodes, and read-out devices comprising single electron transistors.

Abstract: A silicon integrated circuit device comprising a near intrinsic silicon substrate in which there are one or more ohmic contact regions. An insulating layer lies above the substrate, and on top of the insulating layer is a lower layer of one or more aluminium gates. The surface of each of the lower gates is oxidised to insulate them from an upper aluminium gate that extends over the lower gates.

Abstract: This invention concerns interfacing to electronic circuits or systems operating at low temperature or ultra-low temperature using complementary metal-oxide semiconductor (CMOS) technology. Low temperature in this case refers to cryogenic temperatures in particular, but not exclusively, to the 4.2 K region. Ultra-low temperatures here refers to the sub-1 K range, usually accessed using dilution refrigerator systems. The electronic circuits comprise a controller (for writing and manipulation), an observer (for readout and measurement) circuits, or both, fabricated from ultra-thin silicon-on-insulator (SOI) CMOS technology.

Abstract: A silicon substrate is coated with one or more layers of resist. First and second circuit patterns are exposed in sequence, where the second pattern crosses the first pattern. The patterned resist layers are developed to open holes which extend down to the substrate only where the patterns cross over each other. These holes provide a mask suitable for implanting single phosphorous ions in the substrate, for a solid state quantum computer. Further development of the resist layers provides a mask for the deposition of nanoelectronic circuits, such as single electron transistors, aligned to the phosphorous ions.

Abstract: This invention concerns nanoscale products, such as electronic devices fabricated to nanometer accuracy. It also concerns atomic scale products. These products may have an array of electrically active dopant atoms in a silicon surface, or an encapsulated layer of electrically active donor atoms. In a further aspect the invention concerns a method of fabricating such products. The methods include forming a preselected array of donor atoms incorporated into silicon. Encapsulation by growing silicon over a doped surface, after desorbing the passivating hydrogen. Also, using an STM to view donor atoms on the silicon surface during fabrication of a nanoscale device, and measuring the electrical activity of the donor atoms during fabrication of a nanoscale device. Such products and processes are useful in the fabrication of a quantum computer, but could have many other uses.

Abstract: Individual hydrogen atoms are desorbed from a hydrogen terminated layer on a silicon substrate, using an STM tip, to form a pattern of exposed regions. A single donor-bearing molecule (such as phosphorous atoms). The spins of the donor atoms may be used as qubits in a slid quantum computer.

Abstract: This invention concerns a method and system for single ion doping and machining by detecting the impact, penetration and stopping of single ions in a substrate. Such detection is essential for the successful implantation of a counted number of 31P ions into a semi-conductor substrate for construction of a Kane quantum computer. The invention particularly concerns the application of a potential across two electrodes on the surface of the substrate to create a field to separate and sweep out electron-hole pairs formed within the substrate. A detector is then used to detecting transient current in the electrodes, and so determine the arrival of a single ion in the substrate.

Abstract: This invention concerns a method and system for single ion doping and machining by detecting the impact, penetration and stopping of single ions in a substrate. Such detection is essential for the successful implantation of a counted number of 31P ions into a semi-conductor substrate for construction of a Kane quantum computer. The invention particularly concerns the application of a potential across two electrodes on the surface of the substrate to create a field to separate and sweep out electron-hole pairs formed within the substrate. A detector is then used to detecting transient current in the electrodes, and so determine the arrival of a single ion in the substrate.

Abstract: A silicon substrate is coated with one or more layers of resist. First and second circuit patterns are exposed in sequence, where the second pattern crosses the first pattern. The patterned resist layers are developed to open holes which extend down to the substrate only where the patterns cross over each other. These holes provide a mask suitable for implanting single phosphorous ions in the substrate, for a solid state quantum computer. Further development of the resist layers provides a mask for the deposition of nanoelectronic circuits, such as single electron transistors, aligned to the phosphorous ions.

Abstract: Individual hydrogen atoms are desorbed from a hydrogen terminated layer on a silicon substrate, using an STM tip, to form a pattern of exposed regions. A single donor-bearing molecule (such as phosphorous atoms). The spins of the donor atoms may be used as qubits in a slid quantum computer.