Speaker: Cristian Tabares
Venue & Time: 11:30 / Gray Room 3
Abstract: Current experimental quantum devices do not yet meet the requirements for building fault-tolerant quantum computers, but they can still be used to address many-body problems as analogue quantum simulators. Furthermore, recent experimental advances [1-4] are enabling these simulators to operate in a programmable manner [5], where their dynamics can be used as resources to generate a set of (non-universal) quantum gates. These controllable systems are able to generate highly entangled states, but a natural question is how to use these resources for quantum simulation purposes.
In this seminar we will discuss two different approaches. The first one will be based on state preparation, demonstrating how a classical device can be used to assist the analogue quantum simulator in the task of many-body state preparation [6,7] with variational algorithms. We will focus on fermionic atoms in optical lattices [8], constructing for ground-state preparation of local and extended Fermi-Hubbard models that show considerable improvements with respect to equivalent adiabatic methods. Then, in the second part of the talk, we will introduce an algorithm specifically tailored for analog quantum simulators to accurately recover their ground state properties [9]. Using only global time evolution under a target Hamiltonian, our algorithm avoids the need for local control that is typically required in conventional quantum phase estimation.
These results provide programmable quantum simulators with a new set of tools that further leverage their current capabilities. Overall, our work opens new avenues for analog simulators to make a wider and more efficient exploration of their relevant many-body Hilbert space.
[1] X. Zhang et al., Science 379, 278-283 (2023).
[2] C. Kokail et al., Nature 569, 355–360 (2019).
[3] S. Ebadi et al., Nature 595, 227–232 (2021).
[4] D. Bourgund et al., Nature 637, 57–62 (2025).
[5] A. J. Daley et al., Nature 607, 667–676 (2022).
[6] C. Tabares, A. Muñoz de las Heras, L. Tagliacozzo, D. Porras, and A. González-Tudela, Phys. Rev. Lett. 131, 073602 (2023).
[7] A. Muñoz de las Heras, C. Tabares, J. Schneider, L. Tagliacozzo, D. Porras, and A. González-Tudela., Phys. Rev. Research 6, 013299 (2024).
[8] C. Tabares, C. Kokail, P. Zoller, D. González-Cuadra and A. González-Tudela, PRX Quantum 6, 030356 (2025).
[9] C. Tabares, D. S. Wild, J. I. Cirac, P. Zoller, A. Gonzalez-Tudela, and D. González-Cuadra, arXiv:2511.04434 (2025).
