Quantum thermodynamic methods to purify a qubit on a quantum processing unit

Understand

We report on a quantum thermodynamic method to purify a qubit on a quantum processing unit (QPU) equipped with (nearly) identical qubits.

• Our starting point is a three qubit design that emulates the well known two qubit swap engine.
• Similar to standard fridges, the method would allow to cool down a qubit at the expense of heating two other qubits.
• A minimal modification thereof leads to a more practical three qubit design that allows for enhanced refrigeration tasks, such as increasing the purity of one qubit at the expense of decreasing the purity of the other two.