TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysCore.8.4.084
TI  - Quantum adiabaticity in many-body systems and almost-orthogonality in complementary subspace
PY  - 2025/11/12
UR  - https://www.scipost.org/SciPostPhysCore.8.4.084
JF  - SciPost Physics Core
JA  - SciPost Phys. Core
VL  - 8
IS  - 4
SP  - 084
A1  - Chen, Jyong-Hao
AU  - Cheianov, Vadim
AB  - 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},
}