USA As Represented by Secretary of the Navy

Connie H Li

Berend T Jonker

Olaf M J Van 't Erve

Kathleen M Mccreary

Jeremy T Robinson

Ying Liu

Lian Li

Adam L Friedman

Glenn Jernigan

Ramasis Goswami

Aubrey T Hanbicki

Olaf M J Van't Erve

Carl S Hellberg

Olaf M T Van 't Erve

Heterostructures include a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields modulate the charge carriers and carrier density on a nanometer length scale, resulting in the formation of lateral p-n or p-i-n junctions, and variations thereof appropriate for device functions.

Methods for forming lateral heterojunctions in two-dimensional materials integrated with multiferroic layers

Light-emitting devices having lateral heterojunctions in two-dimensional materials integrated with multiferroic layers

The invention relates to heterostructures including a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields modulate the charge carriers and carrier density on a nanometer length scale, resulting in the formation of lateral p-n or p-i-n junctions, and variations thereof appropriate for device functions. Methods for producing the heterostructures are provided. Devices incorporating the heterostructures are also provided.

Lateral heterojunctions in two-dimensional materials integrated with multiferroic layers

A device for directly electrically generating and detecting the current-generated spin polarization in topological insulators, comprising a first and fourth contact on a layer of BiSeand a second contact comprising a ferromagnet/oxide tunnel barrier contact as a detector, and a third contact comprising nonmagnetic metal as a reference contact, a current to the first and fourth contact to produce a net spin polarization, and the spin polarization manifesting as a voltage between the second (magnetic) and third (reference) contacts.

Direct electrical detection of current-induced spin polarization due to spin-momentum locking in topological insulators

A 3C&#x2014;SiC buffer layer on Si(001) comprising a porous buffer layer of 3C&#x2014;SiC on a Si(001) substrate, wherein the porous buffer layer is produced through a solid state reaction, and wherein an amorphous carbon layer on the Si(001) substrate is deposited by magnetron sputtering of a C target at room temperature at a rate of 0.8 nm/min.

Solid phase epitaxy of 3C-SiC on Si(001)

The spin-Hall effect can be used to modulate the linear polarization of light via the magneto-optical Kerr effect. A central area of an outer surface of an added layer atop a spin Hall material is illuminated while simultaneously passing a modulated electric current through the material, so that reflected light has a new linear polarization that differs from the initial linear polarization to a degree depending on the amplitude of the modulated electric current.

Optical modulator using the spin hall effect in metals

The invention relates to heterostructures including a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains and surface charges in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields and surface charges can control the structural phase of the two-dimensional material, which in turn determines whether the two-dimensional material layer is insulating or metallic, has a band gap or no band gap, and whether it is magnetic or non-magnetic. Methods for producing the heterostructures are provided. Devices incorporating the heterostructures are also provided.

Controlling structural phase transitions and properties of two-dimensional materials by integrating with multiferroic layers

The spin-Hall effect can be used to modulate the linear polarization of light via the magneto-optical Kerr effect. A material is illuminated while simultaneously passing a modulated electric current through the material, so that reflected light has a new linear polarization that differs from the initial linear polarization to a degree depending on the amplitude of the modulated electric current.

Method for an optical modulator using the spin hall effect in metals

A method for directly electrically generating and detecting spin polarization in topological insulators comprising depositing a first and fourth contact on a layer of BiSeand applying a current between the contacts, which creates a net spin polarization due to spin-momentum locking. A second (comprising ferromagnet/tunnel barrier) and third contact are deposited for detecting the spin polarization. A device for directly electrically generating and detecting the current-generated spin polarization in topological insulators, comprising a first and fourth contact on a layer of BiSeand a second contact comprising a ferromagnet/oxide tunnel barrier contact as a detector, and a third contact comprising nonmagnetic metal as a reference contact, a current to the first and fourth contact to produce a net spin polarization, and the spin polarization manifesting as a voltage between the second (magnetic) and third (reference) contacts.

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 material&#x2014;graphene. 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.

Homoepitaxial tunnel barriers with functionalized graphene-on-graphene and methods of making

A method of making a SiC buffer layer on a Si substrate comprising depositing an amorphous carbon layer on a Si(001) substrate, controlling the thickness of the amorphous carbon layer by controlling the time of the step of depositing the amorphous carbon layer, and forming a deposited film. A 3C&#x2014;SiC buffer layer on Si(001) comprising a porous buffer layer of 3C&#x2014;SiC on a Si substrate wherein the porous buffer layer is produced through a solid state reaction.

Growing community of inventors

Alexandria, VA, United States of America

Connie H Li