Coupling qubits is provided. The method comprises embedding a tin atom in a silicon substrate and forming a number of quantum dot electrodes over the silicon substrate. The quantum dot electrodes draw an electron from an electron source into the silicon substrate and performing an electron-nuclear controlled-phase gate operation by: moving the electron adiabatically toward the tin atom to achieve a specified level of hyperfine interaction (HFI) between the electron and the nucleus of the tin atom to minimize the effect of noise; holding the electron at the distance of the specified HIFI for a specified duration of time to represent an on state; and moving the electron adiabatically away from the tin atom to lower the HFI below the specified level and represent an off state

Described is a monolithic integrated circuit for use in quantum computing based on single and multiple coupled quantum dot electron- and hole-spin qubits monolithically integrated with the mm-wave spin manipulation and readout circuitry in commercial complementary metal-oxide-semiconductor (CMOS) technology. The integrated circuit includes a plurality of n-channel or p-channel metal-oxide-semiconductor field-effect transistor (MOSFET) cascodes each including a single-spin qubit or two coupled quantum dot qubits formed in an undoped semiconductor film adjacent at least one top gate. There is also a back gate formed in a silicon substrate adjacent a buried oxide layer or the at least one top gate, where the back gate controls the electron or hole entanglement and exchange interaction between the two coupled quantum dot qubits. The monolithic integrated circuits described may be used for monolithically integrated semiconductor quantum processors for quantum information processing.

We disclose a magnetic device having a pair of coplanar thin-film magnetic electrodes arranged on a substrate with a relatively small edge-to-edge separation. In an example embodiment, the magnetic electrodes have a substantially identical footprint that can be approximated by an ellipse, with the short axes of the ellipses being collinear and the edge-to-edge separation between the ellipses being smaller than the size of the short axis. In some embodiments, the magnetic electrodes may have relatively small tapers that extend toward each other from the ellipse edges in the constriction area between the electrodes. Some embodiments may also include an active element inserted into the gap between the tapers and electrical leads connected to the magnetic electrodes for passing electrical current through the active element. When subjected to an appropriate external magnetic field, the magnetic electrodes can advantageously be magnetized to controllably enter parallel and antiparallel magnetization states.

The present invention is directed to an MTJ memory element including a magnetic free layer structure which includes one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagnetic coupling layer opposite the second magnetic reference layer.

The present invention is directed to a magnetic tunnel junction (MTJ) memory element including a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; a magnetic fixed layer exchange coupled to the magnetic reference layer structure through an anti-ferromagnetic coupling layer; a magnesium oxide layer formed adjacent to the magnetic fixed layer; and a metal layer comprising nickel and chromium formed adjacent to the magnesium oxide layer. The magnetic reference layer structure includes a first and a second magnetic reference layers with a first perpendicular enhancement layer (PEL) interposed therebetween. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof. The magnetic fixed layer has a second invariable magnetization direction opposite to the first invariable magnetization direction. The magnetic free layer structure includes one or more magnetic free layers having a variable magnetization direction substantially perpendicular to layer planes thereof.

A data reader may be configured with at least a detector stack positioned on an air bearing surface and consisting of a spin accumulation channel continuously extending from the air bearing surface to an injector stack. The injector stack can have at least one cladding layer contacting the spin accumulation channel. The at least one cladding layer may have a length as measured perpendicular to the ABS that filters minority spins from the detector stack.

The present invention is directed to an MTJ memory element comprising a magnetic free layer structure including one or more magnetic free layers that have a variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure including a first magnetic reference layer and a second magnetic reference layer with a perpendicular enhancement layer interposed therebetween, the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer; and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. The non-magnetic perpendicular enhancement layer includes a first perpendicular enhancement sublayer formed adjacent to the first magnetic reference layer and a second perpendicular enhancement sublayer formed adjacent to the second magnetic reference layer.

The present invention is directed to an STT-MRAM device comprising a plurality of memory elements. Each of the memory elements includes an MTJ structure that comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; a first perpendicular enhancement layer (PEL) formed adjacent to the magnetic free layer structure; a magnetic dead layer formed adjacent to the first PEL; and a magnetic fixed layer exchange coupled to the magnetic reference layer structure through an anti-ferromagnetic coupling layer. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a second PEL. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof.

This disclosure describes a method of making a tunnel barrier-based electronic device, in which the tunnel barrier and transport channel are made of the same materialgraphene. A homoepitaxial tunnel barrier/transport device is created using a monolayer chemically modified graphene sheet as a tunnel barrier on another monolayer graphene sheet. This device displays enhanced spintronic properties over heteroepitaxial devices and is the first to use graphene as both the tunnel barrier and channel.

This disclosure describes a method of making a tunnel barrier-based electronic device, in which the tunnel barrier and transport channel are made of the same materialgraphene. A homoepitaxial tunnel barrier/transport device is created using a monolayer chemically modified graphene sheet as a tunnel barrier on another monolayer graphene sheet. This device displays enhanced spintronic properties over heteroepitaxial devices and is the first to use graphene as both the tunnel barrier and channel.