Unraveling spin entanglement using quantum gates with scanning tunneling microscopy-driven electron spin resonance

Published

October 31, 2025

Author(s)

Eric Switzer, Jose Reina Gálvez, Geza Giedke, Talat Rahman, Christoph Wolf, Deung-Jang Choi, Nicolas Lorente

Abstract

Quantum entanglement is a fundamental resource for quantum information processing, and its controlled generation and detection remain key challenges in scalable quantum architectures. Here, we demonstrate the deterministic generation of entangled spin states in a solid-state platform by implementing quantum gates via electron spin resonance combined with scanning tunneling microscopy (ESR-STM). Using two titanium (Ti) atoms on a MgO/Ag(100) substrate, we construct a two-qubit system whose dynamics are coherently manipulated through tailored microwave pulse sequences. We generate Bell states by implementing a Hadamard gate followed by a controlled-NOT (CNOT) gate, and numerically evaluate its fidelity and concurrence with the TimeESR code. Our results demonstrate that ESR-STM can create entangled states with high/low/average fidelity. This study paves the way for the realization of atom-based quantum circuits and highlights ESR-STM as a powerful tool for probing and engineering entangled states on surfaces.

Citation

Nanoscale Advances

Volume

7

Issue

24

Pub Type

Journals

Download Paper

https://doi.org/10.1039/D5NA00421G

Local Download

Citation

Switzer, E. , Reina Gálvez, J. , Giedke, G. , Rahman, T. , Wolf, C. , Choi, D. and Lorente, N. (2025), Unraveling spin entanglement using quantum gates with scanning tunneling microscopy-driven electron spin resonance, Nanoscale Advances, [online], https://doi.org/10.1039/D5NA00421G, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959878 (Accessed December 9, 2025)