Antenna-coupled graphene Josephson-junction THz/mm-wave apparatus

A method of fabricating an antenna-coupled graphene Josephson-junction THz/mm-wave detector apparatus, the method comprising:

• providing at least one monolayer graphene flake;
• slicing, via a scribe, the at least one monolayer graphene flake thereby forming at least two portions of graphene having substantially the same initial crystallographic orientation wherein each of the at least two portions of graphene are exfoliated up to a size of up to 50 μm;
• stacking the at least two portions of graphene of the monolayer graphene flake with a predetermined rotational misalignment to form a magic-angle graphene stack;
• disposing a first hexagonal boron nitride (“hBN”) flake over at least a portion of a first surface of the magic-angle graphene stack;
• disposing a second hBN flake over an opposing second surface of the magic-angle graphene stack thereby substantially covering the entirety of the second surface of the magic-angle graphene stack;
• providing a stamp having a poly(bisphenol A carbonate) (“PC”) sacrificial layer configured to pick up, transfer, and release two-dimensional material flakes wherein the stamp comprises a plateau edge of approximately 180 μm formed by casting the stamp into a silicon mold patterned by contact photolithography;
• heating the stamp to at least 175° C. to melt and release the PC layer;
• forming, via lithography, at least one bottom-gate (“BG”) contact on a surface of the second hBN flake and at least two top-gate (“TG”) contacts on a surface of the first hBN flake, wherein at least two of the TG contacts are set a predetermined distance from one another to define a Josephson-junction weak-link region;
• and
• disposing, via contact lithography, at least two bowtie antennas on the first surface of the magic-angle graphene stack such that respective wings of the bowtie antennas are electrically coupled to corresponding contact regions on opposite sides of the magic-angle graphene stack, and such that the first hBN flake is interposed between the at least two bowtie antennas.