[NCTS Seminar] Towards Quantum State Tomography from Neutron Scattering
Title: [NCTS Seminar] Towards Quantum State Tomography from Neutron Scattering
Speaker: Dr. Gunnar Möller (University of Kent)
Time: 2026/1/20 (Tue.) 14:00
Place: NCTS Physics Lecture Hall, 4F, Cosmology Hall, NTU
Abstract
Recent theoretical advances suggest that neutron scattering data can be used to infer quantum many-body states, enabling a form of quantum state tomography in magnetic materials. Building on Kohn–Sham-type [1] uniqueness theorems for spin systems [2,3], which establish a one-to-one correspondence between suitable correlators, the Hamiltonian, and the ground state, we analyse the associated inverse problem using numerical and data-driven approaches.We show that distances between structure factors correlate linearly with quantum state overlaps at zero temperature, indicating a well-conditioned “fitness landscape,” with extensions to thermal states, finite clusters, and include the presence of applied fields [4]. Exploiting this structure, we demonstrate that entanglement properties can be accurately learned from neutron-scattering observables using machine learning, even with limited training data and strong transferability across models [5]. These results connect neutron scattering, density-functional ideas, and quantum information in correlated magnets.
[1] P. Hohenberg and W. Kohn, Physical Review 136, B864 (1964).
[2] T. K. Ng, Physical Review B 44, 2407 (1991).
[3] J. Quintanilla, Physical Review B 106, 104435 (2022).
[4] T. Tula, J. Quintanilla, & G. Möller, “Fitness landscape for quantum state tomography from neutron scattering.” Phys. Rev. B 112, L140402 (2025).
[5] T. Tula, PhD Thesis, University of Kent (2025); T. Tula, J. Quintanilla, & G. Möller, in preparation.
