Abstract: Rectification is a process that converts electromagnetic fields into direct current (DC). Such a process underlies a wide range of technologies, including wireless communication, wireless charging, energy harvesting, and infrared detection. Existing rectifiers are mostly based on semiconductor diodes, with limited applicability to small voltages or high frequency inputs. Here, we present an alternative approach to current rectification that uses the electronic properties of quantum crystals without semiconductor junctions. We identify a new mechanism for rectification from skew scattering due to the chirality of itinerant electrons in time-reversal-invariant but inversion-breaking materials. Our calculations reveal large, tunable rectification effects in graphene multilayers and transition metal dichalcogenides. These effects can be used in high-frequency rectifiers by rational material design and quantum wavefunction engineering.

Abstract: An ultrathin, carbon-based memristor with a moiré superlattice potential shows prominent ferroelectric resistance switching. The memristor includes a bilayer material, such as Bernal-stacked bilayer graphene, encapsulated between two layers of a layered material, such as hexagonal boron nitride. At least one of the encapsulating layers is rotationally aligned with the bilayer to create the moiré superlattice potential. The memristor exhibits ultrafast and robust resistance switching between multiple resistance states at high temperatures. The memristor, which may be volatile or nonvolatile, may be suitable for neuromorphic computing.

Abstract: Rectification is a process that converts electromagnetic fields into direct current (DC). Such a process underlies a wide range of technologies, including wireless communication, wireless charging, energy harvesting, and infrared detection. Existing rectifiers are mostly based on semiconductor diodes, with limited applicability to small voltages or high frequency inputs. Here, we present an alternative approach to current rectification that uses the electronic properties of quantum crystals without semiconductor junctions. We identify a new mechanism for rectification from skew scattering due to the chirality of itinerant electrons in time-reversal-invariant but inversion-breaking materials. Our calculations reveal large, tunable rectification effects in graphene multilayers and transition metal dichalcogenides. These effects can be used in high-frequency rectifiers by rational material design and quantum wavefunction engineering.

Abstract: An ultrathin, carbon-based memristor with a moiré superlattice potential shows prominent ferroelectric resistance switching. The memristor includes a bilayer material, such as Bernal-stacked bilayer graphene, encapsulated between two layers of a layered material, such as hexagonal boron nitride. At least one of the encapsulating layers is rotationally aligned with the bilayer to create the moiré superlattice potential. The memristor exhibits ultrafast and robust resistance switching between multiple resistance states at high temperatures. The memristor, which may be volatile or nonvolatile, may be suitable for neuromorphic computing.

Abstract: A locally gated graphene nanostructure is described, along with methods of making and using the same. A graphene layer can include first and second terminal regions separated by a substantially single layer gated graphene nanoconstriction. A local first gate region can be separated from the graphene nanoconstriction by a first gate dielectric. The local first gate region can be capacitively coupled to gate electrical conduction in the graphene nanoconstriction. A second gate region can be separated from the graphene nanoconstriction by a second gate dielectric. The second gate region can be capacitively coupled to provide a bias to a first location in the graphene nanoconstriction and to a second location outside of the graphene nanoconstriction. Methods of making and using locally gated graphene nanostructures are also described.

Abstract: A locally gated graphene nanostructure is described, along with methods of making and using the same. A graphene layer can include first and second terminal regions separated by a substantially single layer gated graphene nanoconstriction. A local first gate region can be separated from the graphene nanoconstriction by a first gate dielectric. The local first gate region can be capacitively coupled to gate electrical conduction in the graphene nanoconstriction. A second gate region can be separated from the graphene nanoconstriction by a second gate dielectric. The second gate region can be capacitively coupled to provide a bias to a first location in the graphene nanoconstriction and to a second location outside of the graphene nanoconstriction. Methods of making and using locally gated graphene nanostructures are also described.