Multidimensional semiclassical single- and double-quantum spectroscopy of anharmonic molecular polaritons

Quantum Physics [Submitted on 22 Apr 2026] Multidimensional semiclassical single- and double-quantum spectroscopy of anharmonic molecular polaritons Michael Reitz, Harsh Bhakta, Wei Xiong, Joel Yuen-Zhou We present a general and efficient approach to compute phase-resolved multidimensional spectra of anharmonic molecular polaritons, based on a semiclassical evolution of the molecular Hamiltonian and cavity field in the large-\mathcal{N} limit of many molecules coupled to a confined photonic mode. By systematically expanding the response in both amplitudes and phases of the input fields, our method enables a transparent and computationally simple construction of phase-cycled two-dimensional single- and double-quantum polariton spectra from the underlying nonlinear signal components. Here, phase cycling acts as an analogue of phase matching with oblique pulses, allowing for the isolation of the contributing nonlinear pathways in Liouville space. We specialize to vibrational polaritons and benchmark the method through direct comparison with experimentally measured single-quantum spectra, providing an explanation for the longstanding puzzle of the polariton bleach effect observed at short waiting times. Further, we show how the imprint of various types of anharmonicities on the double-excitation manifold can be directly probed and analyzed through double-quantum coherence spectroscopy. Taken together, our results establish a practical and powerful framework for the modeling and interpretation of nonlinear spectroscopic experiments on strongly coupled light-matter platforms and for guiding the design of cavity-enhanced molecular platforms. Comments: 12 pages (10 figures) + 10 pages Supplement (6 figures). Includes ancillary GIF file showing a movie of the double-quantum coherence spectrum as a function of excitation time Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Chemical Physics (physics.chem-ph); Optics (physics.optics) Cite as: arXiv:2604.21158 [quant-ph]   (or arXiv:2604.21158v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2604.21158 Focus to learn more Submission history From: Michael Reitz [view email] [v1] Wed, 22 Apr 2026 23:54:15 UTC (4,624 KB) Access Paper: HTML (experimental) view license Ancillary files (details): dqc_movie.gif Current browse context: quant-ph < prev   |   next > new | recent | 2026-04 Change to browse by: cond-mat cond-mat.mes-hall physics physics.chem-ph physics.optics References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)