Previous talks at the SCCS Colloquium

Daniil Teplitskiy: Quantum tomography of spin glasses via time-delayed measurements

SCCS Colloquium |


When characterizing quantum systems, quantum process tomography (QPT) is the standard primitive. But due to the high complexity of quantum systems and the curse of dimensionality, QPT hasn't been implemented for high number of qubits. However, combining QPT and machine learning has shown great success in recent studies. In this thesis, the opportunity is explored of doing QPT in combination with machine learning and quantum circuits, regarding the reconstruction of hamiltonians of spin glasses. This results in a rather simple and straightforward algorithm. Therefore, in the beginning, the necessary quantum circuit is derived. With this, the hamiltonian of an ising model representation is reconstructed. Finally, we switch to spin glasses, which doesn't differ much to the representation by the ising model, and do the same here. From this, the systems are fully characterized by the hamiltonians afterwards. These approaches are done for system sizes of up to 12 qubits, whereas more qubits would be also possible. The results of the reconstructions are reaching high fidelity values using simulated data for the ising model and spin glasses, showing and underlining the efficiency of the proposed algorithm.

Bachelor's thesis talk. Daniil is advised by Irene López Gutiérrez.