The next phase of quantum energy science: from mechanisms to applications

A growing research community spanning quantum batteries, molecular and excitonic energy transport, polaritonics, quantum materials and nuclear control has begun to describe its work in terms of quantum energy or quantum energy science. What connects these otherwise disparate efforts is the deliberate use of quantum states, couplings, collective effects and engineered environments to control energetic states and pathways. A key difference from quantum information science is that the complete quantum state does not always need to be preserved; engineered dissipation or dephasing can even improve the desired outcome. We organize this emerging domain through a framework that connects mechanisms, functions, capabilities, and applications. We identify five elementary functions (Excite, Hold, Release, Transfer, and Transform) and examine the mechanisms that implement them. The same functions recur from the molecular to the nuclear scale, although their relative implementation difficulty can differ sharply. Moving toward technology, we highlight three engineering capabilities (Storage, Routing, and Conversion) through the performance metrics that matter for their applications. Stretch scenarios illustrate what performance targets could make these capabilities technologically consequential.