Superconducting circuits for an A-and-not-B gate having an exclusive-OR gate and an AND gate

A method of operating a circuit for an A-and-not-B gate, wherein the circuit including an output terminal, the method comprising:

• receiving a first set of single flux quantum (SFQ) pulses via a first input terminal;
• receiving a second set of SFQ pulses via a second input terminal;
• performing an exclusive-OR operation on the first set of SFQ pulses received via the first input terminal and the second set of SFQ pulses received via the second input terminal to generate an exclusive-OR result;
• and
• performing an AND operation on the exclusive-OR result and the first set of SFQ pulses received via the first input terminal such that the circuit is configured to pass the first set of SFQ pulses to the output terminal only when inputs to the exclusive-OR operation differ and inputs to the AND operation are the same.

A circuit for an A-and-not-B gate comprising:

• an output terminal;
• a first input terminal for receiving a first set of single flux quantum (SFQ) pulses;
• a powered junction coupled to the first input terminal;
• a second input terminal for receiving a second set of SFQ pulses;
• a first stage configured to perform an exclusive-OR operation on the first set of SFQ pulses received via the first input terminal and the second set of SFQ pulses received via the second input terminal to generate an exclusive-OR result;
• a second stage, coupled to the first stage, configured to perform an AND operation on the exclusive-OR result and the first set of SFQ pulses received via the first input terminal such that the circuit is configured to pass the first set of SFQ pulses to the output terminal only when inputs to the exclusive-OR operation differ and inputs to the AND operation are the same;
• and
• a powered junction coupled to the output terminal.