Quantum information engine using trapped ions

A quantum information engine is an apparatus that converts quantum information into work, where the quantum state measurements become an energy source. We realize a quantum engine with a single trapped-ion system that consists of a qubit and a single vibrational mode, where the measurement results of the qubit are used to give a work on the vibrational mode. In the experiment, the qubit is prepared in a thermal state. Then we measure the qubit state and apply adiabatic blue-sideband transition or red-sideband transition depending on the measurement result. After that, the qubit state is restored to the initial state, which completes the cycle of the engine. Through the cycle, the energy of the mode increases, which is observed by the increase of the average phonon number. We develop a fast detection to minimize the effect on the mode, which can be helpful for number resolving detection of multiple modes.