▎ 摘　　要

NOVELTY - Strain engineered material comprises a graphene sheet comprising an array of wrinkles induced by deformations in the graphene sheet. The deformations are formed by a lattice of underlying nanostructures on a substrate comprising a dielectric material. Each of the wrinkles comprises a ridge aligned on top of a different one of the rows and along an alignment direction defined by the rows. Each deformation pattern induces a periodically varying pseudo magnetic field distribution ranging between a positive value and a negative value. The periodically varying field distribution has field magnitude minima located parallel to and between the ridges. USE - Strain engineered material for a spintronic device, a valley splitter device, Hall effect device, and a transistor. ADVANTAGE - The strain engineering can tune the structural distortion of graphene to achieve desirable electronic properties. The strain-induced pseudo-magnetic field effects from nanoscale to realistic device dimensions to demonstrate useful and tunable device characteristics. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a valley splitter device comprising the strain engineered material, which comprises a first pair of electrodes contacting the graphene sheet and separated by a first distance across the wrinkles to channel a flow of current in the graphene sheet in a direction across the array of wrinkles, where the graphene sheet has an electronic band structure including a first valley and a second valley, and the periodically varying pseudo magnetic field spatially separates the current into a first flow in a first direction and comprising first charge carriers in the first valley and second flow in a second direction and comprising second charge carriers in the second valley; (2) a spintronic device coupled to the valley splitter device and outputting a spin polarized current generated from the first flow; (3) a valley propagator device, which comprises the strain engineered material, which comprises the graphene sheet comprises an electronic band structure including a first valley and a second valley, the device further comprises electrodes electrically contacting the graphene sheet and positioned to channel allow of current in one or more directions parallel to the wrinkles, the current comprises charge carriers comprising at least first charge carriers in the first valley or second charge carriers in the second valley, the periodically varying pseudo magnetic field comprises multiple pairs of adjacent parallel maximum magnitudes of positive and negative magnetic fields, and one or more flows of the charge carriers are confined, in the first valley or the second valley, between adjacent ones of the parallel maximum magnitudes of positive and negative magnetic fields, so that one or more of the multiple pairs guide the current in the one or more directions parallel to the wrinkles and along the alignment direction defined by the rows of nanostructures; (4) a Hall effect device, which comprises the strain engineered material, further comprising a first pair of electrodes positioned to channel a flow of current in graphene sheet along a longitudinal direction parallel to the wrinkles, a second pair of electrodes separated across the wrinkles and measuring a Hall resistance using a voltage generated across the second pair of electrodes in response to the current; and a cooling device thermally coupled to the graphene sheet to cool the graphene sheet to a temperature, where the graphene sheet comprises an electronic band structure including a set of valleys, and the periodically varying pseudo magnetic field interacts with the current to generate an anomalous quantum Hall resistance measured using the voltage and such that the anomalous quantum Hall resistance as a function of the density of charge carriers comprises peaks having values proportional to (h/e2) associated with the charge carriers occupying spin split Landau levels generated in each of the valleys by the periodically varying pseudo magnetic field; (5) a transistor, which comprises the material; and (6) a method of making a strain engineered material, which involves depositing a graphene sheet on a lattice of nanofeatures, where the lattice deforms the graphene sheet to induce a periodic array of wrinkles in the graphene sheet, each of the wrinkles comprise a ridge aligned on top of a different one of the rows and along an alignment direction defined by the rows; the deformations pattern a strain distribution in the graphene sheet that induces a periodically varying pseudo magnetic field distribution ranging between a positive value and a negative value, and the periodically varying pseudo magnetic field distribution has field magnitude minima located parallel to and between the ridges and field magnitude maxima located near to and parallel to each of the ridges.