Superconducting Devices with Ferromagnetic Barrier Junctions

A superconducting memory, comprising:

• an array of memory cells arranged in X-directional rows and Y-directional columns;
• each said memory cell comprising a comparator, said comparator comprising two Josephson junctions (JJ) in series, wherein at least one of said two JJ is a magnetic Josephson junction (MJJ), said MJJ having a barrier that comprises a ferromagnetic material wherein said ferromagnetic material has at least two states of magnetization, each said memory cell further comprising a write port for said MJJ, wherein said write port allows for inducing a switch between said states of magnetization, wherein in one of said states of magnetization said MJJ is capable of generating an output single flux quantum (SFQ) pulse, wherein a binary state of each said memory cell manifests itself as said output SFQ pulse being, or not being, generated by said MJJ;
• and
• X-directional write lines each pertaining to one of said rows, and each coupling to said write port of each of said memory cell of said one row, and Y-directional write lines each pertaining to one of said columns, and each coupling to said write port of each of said memory cell of said one column, wherein a selected X-directional write line and a selected Y-directional write line in their combination are capable of said inducing of said switch between said states of magnetization in said memory cell that is located at the intersection of said selected X-directional write line and said selected Y-directional write line.

A method, comprising:

• implementing a comparator having two Josephson junctions (JJ) in series, wherein one of said two JJ being a magnetic Josephson junction (MJJ) having a barrier that comprises a ferromagnetic material, wherein said ferromagnetic material has at least two states of magnetization, wherein said comparator has an output port;
• providing a write port for said MJJ, wherein said write port allows for inducing a switch between said states of magnetization;
• applying a single flux quantum (SFQ) pulse onto said comparator, wherein for one of said states of magnetization said MJJ generates a response SFQ pulse on said output port of said comparator;
• and
• wherein said method is characterized as producing a superconducting memory where a binary state in said superconducting memory manifests itself as said response SFQ pulse appearing, or not appearing, on said output port.