Implementing a Quantum Information Engine Using Spintronics

Quantum information engines can transform information gained from a quantum measurement into available work. Beyond theoretical constructs, such engines are typically studied using optical/microwave strokes on localized electron states (e.g. NV− centers in diamond). This Chapter describes a spin electronic implementation of this engine construct. After reviewing prior spintronic experiments that might be described as manifestations of this engine class, we present recent experiments and theory that describe how a quantum information engine can be assembled using spintronics. Herein, we emphasize the importance of the ferromagnetic metal/molecule interface as the apparatus to measure the quantum spin state of fluctuating paramagnetic centers borne by stand-alone and molecule-embedded atoms. This construct utilizes the underpinnings of its solid-state design to advantageously exhibit inherent quantum coherence between these paramagnetic atoms, along a quantization axis defined by the measurement apparatus. We highlight the need for further insight using auxiliary experiments. Retooling the industrial chain that commercializes magnetic memories to implement this concept could enable mid-term applications to harvest ambient thermal energy.