Entanglement is believed to be an important resource for quantum computation. With the development of relatively large scale (128-qubit) quantum annealing processors, the question of whether such processors can generate and utilize entanglement between their qubits, especially in the presence of a thermal environment, becomes crucial. In this presentation, I will provide experimental evidence for the presence of entangled eigenstates in the multi-qubit energy spectrum of the processor when implementing example problems. The eigenstates are detected using a newly developed tunneling spectroscopy technique and the resulting eigen-spectrum is compared with the theoretical predictions. I will also show that the thermal mixed state of the processor can become entangled during the quantum annealing of these problems. Such thermal entanglement is robust and does not vanish with time, indicating that the processor can employ robust quantum resources for solving problems.
sig. Matthias Troyer