Moving Towards Compactification of the Many-Body Wavefunction

Topic:
Moving Towards Compactification of the Many-Body Wavefunction

Summary:
In the first part of this talk, Bruna will discuss the e cient estimation of physical observables in lattice systems, as outlined in our recent work (Phys. Rev. A 106, 062441, 2022). Estimating the complete quantum state of many-body systems often involves dealing with an exponentially growing number of parameters as the system size increases. However, in specific scenarios, we can narrow our focus to a subset of these parameters, eliminating the need for full state reconstruction. One such scenario involves determining reduced states up to a specific size, where overlapping tomography proves invaluable. This approach significantly reduces the number of measurements required compared to independent
tomog raphy for each reduced state. She will particularly highlight the relevance of this technique in systems with a natural notion of locality, especially when interest centers on the reduced states of neighboring particles. Notably, local overlapping tomography does not exhibit an increasing demand for product-measurement settings with growing system size. I will also introduce tailored strategies for qubit and fermionic systems in selected lattice geometries. These methods are particularly useful in estimating many-body systems prepared in contemporary quantum simulators or quantum computing devices, where interactions often exhibit locality.

In the second part of this talk, Bruna will describe her
ef forts in developing a versa tile toolbox for addressing many-body fermionic systems. This toolbox utilizes various techniques, including transcorrelation, DMRG, compressed quantum cir cuits, bipartite graph theory, as well as elements of bootstrap and conformal bootstrap. She will bring her perspective from theoretical physics to the quantum computing community's usual toolkit. In particular, she will explore how valuable tools from quantum gravity can enhance our understanding of quantum chemistry systems. By combining these approaches, we aim to tackle ab initio Hamiltonians with a broader range of techniques, offering new insights into complex quantum systems.

Bio:
Bruna G. M. Araújo is a postdoctoral researcher investigating vari ational algorithms for electronic transcorrelated Hamiltonians. She completed a one-year postdoctoral appointment at the Center for Quantum Information and Control (CQuIC) at the University of New Mexico (UNM) in Prof. Aki masa Miyake's group. She earned her Ph.D. with Summa Cum Laude honors from The Autonomous University of Barcelona (UAB), where she conducted her research in two diff erent institutes affiliated with the Barcelona Institute of Science and Technology (BIST). The rest part of her thesis focused on the exploration of entanglement in graphene-based materials under the supervision of Prof. Stephan Roche and Dr. Aron Cummings at ICN2. The second part delved into the study of many-body quantum states under the guidance of Prof. Antonio Acin at ICFO. Her thesis, titled 'Quantum Information in Lattices,' was funded by a Marie Sklodowska-Curie fellowship. During her Ph.D., she worked in part-time at IBM Quantum and was actively involved in the Qiskit Quantum Community, where she contributed to teaching, mentorship, commu nity building, and cutting-edge research. Before commencing her Ph.D., she received training in the Conformal Bootstrap program. Bruna earned both a Bachelor's and a Master's degree in Theoretical Physics and Chemical Engineering in Recife, Brazil

Moderators:
Pawel Gora, CEO of Quantum AI Foundation and Dr. Sebastian Zajac, member of QPoland