Certifying Nonlocal Spin Quantum Entanglement from Local Tunneling Spectra
Abstract
Quantum entanglement is intrinsically nonlocal, whereas tunneling spectroscopy measures one site at a time. We show that this apparent mismatch can be overcome: local tunneling spectra can certify spin entanglement without coherent control or absolute intensity calibration. An exact spin sum rule turns the high-bias conductance into an internal normalization, allowing the inelastic spin-flip weight to place a lower bound on the local quantum Fisher information. Total-spin conservation then fixes the otherwise inaccessible intersite fluctuation, converting two local spectra into a bound on a collective entanglement witness. We incorporate coupling to the substrate through a spectroscopic bound on spin leakage, while a hierarchy of thresholds distinguishes entanglement between the spins from entanglement with their environment. Including instrumental broadening and noise, the resulting certificate holds at a stated confidence level. These results establish a route for extracting nonlocal quantum information from equilibrium local spectroscopy.
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BibTeX
@misc{kazemikhah2026certifying,
title = {{Certifying Nonlocal Spin Quantum Entanglement from Local Tunneling Spectra}},
author = {Payman Kazemikhah and Ruolun Zhang and Xiangyu Luo and Byunghoon Kim and Yu-Peng Zhu and Md. Shafayat Hossain and M. Zahid Hasan},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.24440},
eprint = {2610.24440},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.24440},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Certifying Nonlocal Spin Quantum Entanglement from Local Tunneling Spectra
AU - Payman Kazemikhah
AU - Ruolun Zhang
AU - Xiangyu Luo
AU - Byunghoon Kim
AU - Yu-Peng Zhu
AU - Md. Shafayat Hossain
AU - M. Zahid Hasan
PY - 2026
DA - 2026/10/17
PB - arXiv
DO - 10.48550/arxiv.2610.24440
UR - https://arxiv.org/abs/2610.24440
AB - Quantum entanglement is intrinsically nonlocal, whereas tunneling spectroscopy measures one site at a time. We show that this apparent mismatch can be overcome: local tunneling spectra can certify spin entanglement without coherent control or absolute intensity calibration. An exact spin sum rule turns the high-bias conductance into an internal normalization, allowing the inelastic spin-flip weight to place a lower bound on the local quantum Fisher information. Total-spin conservation then fixes the otherwise inaccessible intersite fluctuation, converting two local spectra into a bound on a collective entanglement witness. We incorporate coupling to the substrate through a spectroscopic bound on spin leakage, while a hierarchy of thresholds distinguishes entanglement between the spins from entanglement with their environment. Including instrumental broadening and noise, the resulting certificate holds at a stated confidence level. These results establish a route for extracting nonlocal quantum information from equilibrium local spectroscopy.
ER -