Recorded 28 March 2022. Giulia Galli of the University of Chicago, Chemistry, presents "Embedding theories for quantum simulations on hybrid classical-quantum architectures" at IPAM's Multiscale Approaches in Quantum Mechanics Workshop. Abstract: We discuss a quantum embedding theory [1] to study spin-defects and impurities in solids, which is scalable to large systems and represents an important step towards multiscale calculations of heterogeneous systems. We compare the theory (which we call quantum defect embedding [QDET]) with other embedding frameworks, pointing out differences and similarities and target applications. We also present calculations on classical and quantum computers of the electronic structure of qubits performed with QDET [2]. [1] He Ma, Marco Govoni and Giulia Galli, npj, Comput. Mat., 6 (85), (2020); He Ma, Nan Sheng, Marco Govoni and Giulia Galli, J. Chem. Theory Comput., 17, 2116-2125 (2021); N. Sheng, C. Vorwerk, M.Govoni and Giulia Galli https://arxiv.org/abs/2203.05493 [2] Benchen Huang, Marco Govoni, and Giulia Galli, PRX Quantum 3, 010339 (2022). Learn more online at: http://www.ipam.ucla.edu/programs/workshops/workshop-i-multiscale-approaches-in-quantum-mechanics/?tab=schedule