Topologically-protected traveling-wave amplifier

A topologically-protected traveling-wave amplifier comprising:

• a plurality of resonators arranged in a two-dimensional array (TDA), the plurality of resonators being arranged to define a periphery including a first edge, each resonator being coupled to neighboring resonators of the TDA;
• an input line coupled to an input resonator of the plurality of resonators, the input resonator being disposed along the first edge;
• an output line coupled to an output resonator of the plurality of resonators, the output resonator being disposed along the first edge and being spaced from the input resonator by at least one other resonator of the plurality of resonators;
• a synthetic gauge field generator (SGFG) associated with the plurality of resonators, the SGFG and the plurality of resonators being configured to provide a topologically-protected edge state for the TDA, the topologically-protected edge state corresponding to propagation along the periphery in a propagation direction from the input resonator along the first edge to the output resonator;
• and
• a parametric driving element coupled to the plurality of resonators, the parametric driving element being configured to create pairs of photons in the topologically protected edge state and thereby amplify a signal propagating along the first edge in the propagation direction,
• whereby
• an input signal incident from the input line on the input resonator propagates in the propagation direction along the first edge while being amplified and is detected at the output line as an amplified signal, and
• a signal incident from the output line is attenuated before emerging at the input resonator.