{"quality_controlled":"1","volume":136,"intvolume":"       136","OA_place":"publisher","article_number":"106901","publication":"Physical Review Letters","scopus_import":"1","type":"journal_article","author":[{"full_name":"Shen, Chao","id":"f84c083e-dc8d-11ea-abe3-aaf3d822a8bb","last_name":"Shen","first_name":"Chao"},{"full_name":"Frenzel, Maximilian","first_name":"Maximilian","last_name":"Frenzel"},{"first_name":"Sebastian F.","last_name":"Maehrlein","full_name":"Maehrlein, Sebastian F."},{"last_name":"Alpichshev","first_name":"Zhanybek","orcid":"0000-0002-7183-5203","full_name":"Alpichshev, Zhanybek","id":"45E67A2A-F248-11E8-B48F-1D18A9856A87"}],"corr_author":"1","date_published":"2026-03-13T00:00:00Z","language":[{"iso":"eng"}],"month":"03","OA_type":"hybrid","issue":"10","file":[{"checksum":"712b05b4b0e0fbe9fd426a8c9d41ce20","access_level":"open_access","file_name":"2026_PhysicalReviewLetters_Shen.pdf","relation":"main_file","success":1,"content_type":"application/pdf","file_id":"21475","date_created":"2026-03-23T13:08:06Z","creator":"dernst","date_updated":"2026-03-23T13:08:06Z","file_size":1375532}],"status":"public","publication_identifier":{"eissn":["1079-7114"],"issn":["0031-9007"]},"oa_version":"Published Version","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","_id":"21469","PlanS_conform":"1","has_accepted_license":"1","year":"2026","publication_status":"published","tmp":{"name":"Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)","short":"CC BY (4.0)","image":"/images/cc_by.png","legal_code_url":"https://creativecommons.org/licenses/by/4.0/legalcode"},"article_type":"original","abstract":[{"lang":"eng","text":"Terahertz (THz) spectroscopy is a powerful probe of low-energy excitations in complex materials. Extending it into the nonlinear regime broadens its scope and can provide valuable insight into interactions among these modes. However, interpreting nonlinear spectra is challenging because resonant features in this case do not always reflect intrinsic material dynamics. Here, we study nonlinear THz-induced Kerr effect in a generic material LaAlO3. After detailed analysis of temporal oscillations of the Kerr signal, we identify an 𝐸𝑔 Raman mode at 1.1 THz excited through a two-photon process, while two additional peaks (0.86 and 0.36 THz) arise from phase matching of the near-infrared probe beam with co- and counterpropagating THz pump fields, mediated by off-resonant electronic hyperpolarizability. These results demonstrate the crucial role of kinematic effects in shaping THz-induced Kerr response and establish a framework for interpreting nonlinear spectroscopies in complex materials."}],"oa":1,"date_created":"2026-03-22T23:04:31Z","publisher":"American Physical Society","title":"Disentangling electronic and ionic nonlinear polarization effects in bulk THz Kerr response","department":[{"_id":"ZhAl"},{"_id":"GradSch"}],"file_date_updated":"2026-03-23T13:08:06Z","acknowledgement":"Z. A. acknowledges support from the collaborative research project SFB Q-M&S funded by the Austrian Science Fund (FWF, Grant No. PR1050F8602). S. F. M. acknowledges support and funding from the Deutsche Forschungsgemeinschaft (DFG, Grant No. 469405347).","doi":"10.1103/1c5k-9z82","citation":{"short":"C. Shen, M. Frenzel, S.F. Maehrlein, Z. Alpichshev, Physical Review Letters 136 (2026).","ieee":"C. Shen, M. Frenzel, S. F. Maehrlein, and Z. Alpichshev, “Disentangling electronic and ionic nonlinear polarization effects in bulk THz Kerr response,” <i>Physical Review Letters</i>, vol. 136, no. 10. American Physical Society, 2026.","ama":"Shen C, Frenzel M, Maehrlein SF, Alpichshev Z. Disentangling electronic and ionic nonlinear polarization effects in bulk THz Kerr response. <i>Physical Review Letters</i>. 2026;136(10). doi:<a href=\"https://doi.org/10.1103/1c5k-9z82\">10.1103/1c5k-9z82</a>","chicago":"Shen, Chao, Maximilian Frenzel, Sebastian F. Maehrlein, and Zhanybek Alpichshev. “Disentangling Electronic and Ionic Nonlinear Polarization Effects in Bulk THz Kerr Response.” <i>Physical Review Letters</i>. American Physical Society, 2026. <a href=\"https://doi.org/10.1103/1c5k-9z82\">https://doi.org/10.1103/1c5k-9z82</a>.","apa":"Shen, C., Frenzel, M., Maehrlein, S. F., &#38; Alpichshev, Z. (2026). Disentangling electronic and ionic nonlinear polarization effects in bulk THz Kerr response. <i>Physical Review Letters</i>. American Physical Society. <a href=\"https://doi.org/10.1103/1c5k-9z82\">https://doi.org/10.1103/1c5k-9z82</a>","ista":"Shen C, Frenzel M, Maehrlein SF, Alpichshev Z. 2026. Disentangling electronic and ionic nonlinear polarization effects in bulk THz Kerr response. Physical Review Letters. 136(10), 106901.","mla":"Shen, Chao, et al. “Disentangling Electronic and Ionic Nonlinear Polarization Effects in Bulk THz Kerr Response.” <i>Physical Review Letters</i>, vol. 136, no. 10, 106901, American Physical Society, 2026, doi:<a href=\"https://doi.org/10.1103/1c5k-9z82\">10.1103/1c5k-9z82</a>."},"ddc":["530"],"article_processing_charge":"Yes (via OA deal)","date_updated":"2026-03-23T13:11:09Z","day":"13","project":[{"name":"Center for Correlated Quantum Materials and Solid State Quantum Systems: Nonlinear THz spectroscopy of quantum critical materials","grant_number":"F8602","_id":"34a97cc6-11ca-11ed-8bc3-9acbba792f33"}]}