Transistors and methods of forming the same include forming a fin that has an active layer between two sacrificial layers. Material from the two sacrificial layers is etched away in a region of the fin. A gate stack is formed around the active layer in the region. Source and drain regions are formed in contact with the active layer.

Provided is a logical operation element that performs logical operations on three or more inputs using a single unique device. The logical operation element 30 is provided with an electrode 5A and the other electrode 5B that are provided to have a nanogap, a metal nanoparticle 7 arranged between the electrode 5A and the other electrode 5B in insulated state, and a plurality of gate electrodes 5C, 5D, 11, 11A, 11B for adjusting a charge of the metal nanoparticle 7. Electric current that flows between the electrode 5A and the other electrode 5B is controlled in accordance with the voltage applied to three or more of the gate electrodes 5C, 5D, 11, 11A, 11B.

A silicon-based quantum dot device (1) is disclosed. The device comprises a substrate (8) and a layer (7) of silicon or silicon-germanium supported on the substrate which is configured to provide at least one quantum dot (5.sub.1, 5.sub.2: FIG. 5). The layer of silicon or silicon-germanium has a thickness of no more than ten monolayers. The layer of silicon or silicon-germanium may have a thickness of no more than eight or five monolayers.

A spin qubit quantum device, comprising: a semiconductor portion comprising a first region disposed between two second regions; a first control gate disposed in direct contact with the first region and configured to control a minimum potential energy level in the first region, and disposed in direct contact with a first face of the semiconductor portion; and second electrostatic control gates, each disposed in direct contact with one of the second regions and configured to control a maximum potential energy level in one of the second regions, and disposed in direct contact with a second face, opposite to the first face, of the semiconductor portion, and wherein the first gate is not aligned with the second gates.

A qubit device includes a crystal immobilized on a substrate and in contact with electrodes. The crystal exhibits a charge pair symmetry and with an electron current moving clockwise, counter clockwise, or both. The current in can be placed in a state of superposition wherein the current is unknown until it is measured, and the direction of the current is measured to produce a binary output corresponding to a logical zero or a logical one. A state of the qubit device is monitored by measuring a voltage, a current, or a magnetic field and assigning a superposition or base state depending on a threshold value.

Quantum information processing apparatus and methods are described. The apparatus comprises a device for defining a qubit and a reflectometry circuit for reading out a state of the qubit. The device comprises a semiconductor nanowire extending along a first direction having first and second obtuse or acute edges running along the first direction, gate dielectric overlying the first and second edges of the nanowire and a split gate running across a section of the nanowire in a second, transverse direction, the split gate comprising first and second gates overlying the first and second edges respectively. The reflectometry circuit comprises a resonator coupled to the first or second gate.

Disclosed herein are single electron transistor (SET) devices, and related methods and devices. In some embodiments, a SET device may include: first and second source/drain (S/D) electrodes; a plurality of islands, disposed between the first and second S/D electrodes; and dielectric material disposed between adjacent ones of the islands, between the first S/D electrode and an adjacent one of the islands, and between the second S/D electrode and an adjacent one of the islands.

A semiconductor device includes a substrate; a plurality of gate stacks situated horizontally following one another on the substrate, each gate stack including a layer of a dielectric material in contact with the substrate and a layer of a conductive material on the layer of dielectric material; a source and a drain situated on the substrate on either side of the plurality of gate stacks; a plurality of first spacers made of a first dielectric material, called secondary spacers, having a first width, called width of the secondary spacers, the source and the drain being separated from the closest gate stack by a secondary spacer; at least one main spacer made of a second dielectric material, a main spacer being situated between each gate stack, the width of the main spacer(s) being greater than the width of the secondary spacers.

A method for processing a semiconductor device with two closely space gates comprises forming a template structure, wherein the template structure includes at least one sub-structure having a dimension less than the CD. The method further comprises forming a gate layer on and around the template structure. Then, the method comprises removing the part of the gate layer formed on the template structure, and patterning the remaining gate layer into a gate structure including the two gates. Further, the method comprises selectively removing the template structure, wherein the spacing between the two gates is formed by the removed sub-structure.

The present invention relates to a method for forming nano-gaps in graphene. The method may include applying a voltage across a region of graphene such that a nano-gap which extends across the entire width of the graphene is formed, wherein the region across which the voltage is applied may include a point which is the narrowest in the region.