  Experiments over the past years have demonstrated that it is possible to
bring nanomechanical resonators and superconducting qubits close to the quantum
regime and to measure their properties with an accuracy close to the Heisenberg
uncertainty limit. Therefore, it is just a question of time before we will
routinely see true quantum effects in nanomechanical systems. One of the
hallmarks of quantum mechanics is the existence of entangled states. We propose
a realistic scenario making it possible to detect entanglement of a mechanical
resonator and a qubit in a nanoelectromechanical setup. The detection scheme
involves only standard current and noise measurements of an atomic point
contact coupled to an oscillator and a qubit. This setup could allow for the
first observation of entanglement between a continuous and a discrete quantum
system in the solid state.

Mesoscale and Nanoscale Physics