Design Constraints on a Unruh-DeWitt Quantum Computer.

A quantum computer that utilizes both stationary qubits, as well as flying qubits could provide new insights into quantum computing as well as quantum materials. Well-known and experimentally verified condensed matter systems, such as Luttinger liquids utilizing fermionic edge states, coupled to spin qubits create a quantum bus that performs all-to-all connected operations using stationary and flying qubits. Modeling the qubit-field interactions with Unruh-DeWitt detectors introduces novel quantum devices that offer promising results for computations that pass quantum information from one stationary qubit to another via flying qubit. To see this, we explore Relativistic Quantum Information theory, where there has been significant progress using scalar fields to evaluate quantum information passing onto and off of quantum fields in the regime of strong coupling, a requirement of quantum computing. However, there has been less progress with theories for strongly coupled Dirac fermions. Through bosonization, we show Unruh-DeWitt detectors can process quantum information on channels with near-perfect channel capacity and do so with fermionic Flying Qubits. Through theory and simulation, our results point the way toward the experimental study of quantum information in quantum fields via condensed matter physics.