Non-Polaritonic Effects in Cavity-Modified Photochemistry

Strong coupling of molecules to vacuum fields is widely reported to lead to modified chemical properties such as reaction rates. However, some recent attempts to reproduce infrared strong coupling results have not been successful, suggesting that factors other than strong coupling may sometimes be involved. In the first vacuum-modified chemistry experiment, changes to a molecular photoisomerization process in the ultraviolet-visible spectral range are attributed to strong coupling of the molecules to visible light. Here, this process is re-examined, finding significant variations in photoisomerization rates consistent with the original work. However, there is no evidence that these changes need to be attributed to strong coupling. Instead, it is suggested that the photoisomerization rates involved are most strongly influenced by the absorption of ultraviolet radiation in the cavity. These results indicate that care must be taken to rule out non-polaritonic effects before invoking strong coupling to explain any changes of properties arising in cavity-based experiments. Strong light-matter coupling might modify material properties including chemical processes. Here, the first vacuum-modified chemistry experiment, studying cavity-modified photochemistry, is re-examined. Changes in photoisomerization rate are explained by the absorption of ultraviolet radiation in the cavity with no evidence that these changes need to be attributed to strong coupling. This work highlights the importance of systematic experimentation to rule out non-polaritonic effects.image

Automated summary

This study re-examines the impact of infrared strong coupling on photoisomerization rates and finds that the variations observed can be attributed to the absorption of ultraviolet radiation in the cavity, rather than strong coupling. The results highlight the importance of ruling out non-polaritonic effects in cavity-based experiments.