Quantum adiabaticity in many-body systems and almost-orthogonality in complementary subspace, by Jyong-Hao Chen, Vadim Cheianov

SciPost Physics Core Home Authoring Refereeing Submit a manuscript About Quantum adiabaticity in many-body systems and almost-orthogonality in complementary subspace Jyong-Hao Chen, Vadim Cheianov SciPost Phys. Core 8, 084 (2025) · published 12 November 2025 doi: 10.21468/SciPostPhysCore.8.4.084 pdf BiBTeX RIS Submissions/Reports Abstract We investigate why, in quantum many-body systems, the adiabatic fidelity and the overlap between the initial state and instantaneous ground states often yield nearly identical values. Our analysis suggests that this phenomenon results from an interplay between two intrinsic limits of many-body systems: the limit of small evolution parameters and the limit of large system sizes. In the former case, conventional perturbation theory provides a straightforward explanation. In the latter case, a key insight is that pairs of vectors in the Hilbert space orthogonal to the initial state tend to become nearly orthogonal as the system size increases. We illustrate these general findings with two representative models of driven many-body systems: the driven Rice-Mele model and the driven interacting Kitaev chain model. × TY - JOURPB - SciPost FoundationDO - 10.21468/SciPostPhysCore.8.4.084TI - Quantum adiabaticity in many-body systems and almost-orthogonality in complementary subspacePY - 2025/11/12UR - https://scipost.org/SciPostPhysCore.8.4.084JF - SciPost Physics CoreJA - SciPost Phys. CoreVL - 8IS - 4SP - 084A1 - Chen, Jyong-HaoAU - Cheianov, VadimAB - We investigate why, in quantum many-body systems, the adiabatic fidelity and the overlap between the initial state and instantaneous ground states often yield nearly identical values. Our analysis suggests that this phenomenon results from an interplay between two intrinsic limits of many-body systems: the limit of small evolution parameters and the limit of large system sizes. In the former case, conventional perturbation theory provides a straightforward explanation. In the latter case, a key insight is that pairs of vectors in the Hilbert space orthogonal to the initial state tend to become nearly orthogonal as the system size increases. We illustrate these general findings with two representative models of driven many-body systems: the driven Rice-Mele model and the driven interacting Kitaev chain model.ER - × @Article{10.21468/SciPostPhysCore.8.4.084, title={{Quantum adiabaticity in many-body systems and almost-orthogonality in complementary subspace}}, author={Jyong-Hao Chen and Vadim Cheianov}, journal={SciPost Phys. Core}, volume={8}, pages={084}, year={2025}, publisher={SciPost}, doi={10.21468/SciPostPhysCore.8.4.084}, url={https://scipost.org/10.21468/SciPostPhysCore.8.4.084},} Ontology / Topics See full Ontology or Topics database. Adiabatic ramps Quantum many-body systems Authors / Affiliations: mappings to Contributors and Organizations See all Organizations. 1 2 Jyong-Hao Chen, 1 Vadim Cheianov 1 Universiteit Leiden / Leiden University [UL] 2 National Central University [NCU] Funders for the research work leading to this publication Ministry of Science and Technology, Taiwan (through Organization: National Science and Technology Council [NSTC]) Nederlandse Organisatie voor Wetenschappelijk Onderzoek / Netherlands Organisation for Scientific Research [NWO]