Theoretical prediction for monitoring Jahn-Teller vibrational evolution using real-space tip-enhanced Raman imaging

Article https://doi.org/10.1038/s41467-025-67894-z Theoretical prediction for monitoring JahnTeller vibrational evolution using real-space tip-enhanced Raman imaging Received: 23 June 2025 1234567890():,; 1234567890():,; Accepted: 11 December 2025 Check for updates Hai-Zhen Yu1, Rui-Lin Han2, Dingwei Chu1, Yuanzhi Li1, Xiao-Ru Dong3, Yang Zhang 2,3, Li Wang1, Yuzhi Song 1, Chuan-Kui Wang1, Zhen Xie Sai Duan 4,5 1 & The Jahn-Teller effect (JTE) reduces the geometrical symmetry of a system with degenerate electronic states via vibronic coupling, playing a pivotal role in molecular and condensed systems. However, due to the intrinsic limitations of conventional techniques, only the electronic evolution in JTE can be measured. Herein, we theoretically propose that vibrational resolved tip-enhanced Raman scattering images can visualize the vibrational evolutions in JTE in real space. Taking an experimentally accessible single zinc phthalocyanine (ZnPc) molecule as a proof-of-principle example, not only the degenerate vibrational splitting but also the overlooked vibration mixing caused by the JTE in its anionic form can be characterized by Raman images. Leveraging Raman images, the controllable configuration of JTE distortion with partial isotopic substitution can be further identified. These findings establish a practical protocol to monitor the detailed vibrational evolutions when a single molecule experiences JTE, providing a pathway for visualization of spontaneous symmetry breaking in molecular and solid-state systems. The Jahn-Teller effect (JTE)1,2 describes a fundamental phenomenon that a degenerate system spontaneously reduces its geometry symmetry via the vibronic coupling to stabilize the total energy3–5. JTE represents a general mechanism of spontaneous symmetry breaking, which is responsible for various important observations across multiple disciplines, including spectroscopy, molecular and solid-state physics, stereochemistry, and materials science6–14. In practice, JTE can be efficiently induced by injecting or removing an electron from a degenerate electronic state15,16, particularly in systems containing transition metal ions7,17,18. Such a charge-induced JTE arises from the modification of electronic occupancy, which directly lifts the degeneracy of molecular orbitals and thereby triggers symmetrylowering structural distortions. In this context, scanning probe microscopy (SPM) techniques provide a practical means to precisely control JTE in real space19,20. Despite the success of SPM techniques in the visualization of JTE, most investigations were focused on imaging the symmetry breaking of electronic states21–25. Exclusive investigation on the electronic degrees of freedom in JTE has led to the current lack of understanding of its vibrational aspect, which results in potentially ambiguous assignments of accompanying frequency splitting, the mixing of vibrational wavefunctions upon symmetry reduction, and the 1 Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan, P. R. China. 2School of Physics, University of Science and Technology of China, Hefei, Anhui, P. R. China. 3Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, P. R. China. 4State Key Laboratory of Porous Materials for Separation and Conversion, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Research Center for Chemical Theory, Department of Chemistry, Fudan e-mail: ; University, Shanghai, P. R. China. 5Hefei National Laboratory, Hefei, P. R. China. Nature Communications | (2026)17:1132 1 Article https://doi.org/10.1038/s41467-025-67894-z Results possibility of controlling JTE distortions through atomic displacements. Recently, by leveraging the tip-enhanced Raman scatting (TERS)26–29, an experimental measurement has captured several spectral variations when a single zinc phthalocyanine (ZnPc) was negatively charged30, where vibrational frequency evolution was highlighted. Nevertheless, it still lacks further reports on imaging vibrational symmetry breaking, another essential aspect of JTE, although it is possible owing to the high spatial resolution of TERS31–35. Recent TERS studies have demonstrated their ability to quantitatively map the spatial distribution of vibrational wave functions32,36–39. In this study, this technique is expected to be further extended to visualize the single-molecule JTE from the vibrational perspective. Taking the experimentally accessible ZnPc molecule as a proof-ofprinciple example, we theoretically propose that TERS images provide a practical means to monitor all the details of the vibrational evolution in JTE distortion. We demonstrate that, not only the splitting of degenerate vibrations but also the mixing of non-degenerate vibrations belonging to different irreducible representations of the highsymmetry point group, can be affirmatively observed in TERS images. For the latter case, we reveal that the mixing strength is determined by both the energy difference and spatial distribution overlap between the mixed modes. Moreover, we manifest that the controllable JTE distortions at the sub-ångström level achieved through partial isotope substitution can be unambiguously distinguished by high-resolution TERS imaging. a Spectra characterization of charge-induced JTE Figure 1a illustrates the experimental setup for injecting an electron into neutral ZnPc to induce JTE distortion. In the neutral state, ZnPc possesses a doubly degenerate lowest unoccupied molecular orbital. Upon adding an extra electron, this degeneracy is lifted, triggering a symmetry-lowering structural distortion. Previous experiments observed sudden changes in TERS spectra when the sample bias exceeded 0.3 V, which was assigned as a transition from the neutral to negatively charged state30. It should be stressed that owing to the insulating spacer layer introduced in Fig. 1a, the negatively charged ZnPc− has a sufficiently long lifetime for spectral measurements and even imaging30,40. Besides, the experiment explicitly ruled out molecular deformation induced by mechanical pressure from the tip apex. Specifically, the reproducible spectral evolution during tip approach and retraction confirmed that the observed spectral changes and symmetry reduction originated intrinsically from different charging states of ZnPc30. Calculations show that the JTE-induced geometrical distortion from the neutral D4h to the anionic D2h is quite subtle (the elongations along both the diagonal axes are 0.026 and 0.010 Å, respectively, as shown in Fig. 1b), which provides an ideal example for focusing exclusively on vibrational variation itself. To efficiently excite the requir (...truncated)