The goal of the fellowship is to build an ultrasensitive two-dimensional infrared spectrometer and apply it to detection of complex mixtures of trace amounts of volatile organic compounds (VOCs). Third-order spectroscopies using ultrashort pulses, such as 2D IR spectroscopy, are powerful tools for studying both structure and dynamics. They probe the evolution of state-to-state coherences between quantum states and evolution of state populations on femtosecond to nanosecond timescales, in between excitation by ultrashort optical pulses. In terms of molecular properties, 2D IR spectroscopy probes correlations between molecular bonds, which strongly depend on the structure of the molecule as a whole. Compared to linear spectroscopy, which is more bond-specific, 2D IR spectroscopy provides much greater selectivity. Compared to mass spectrometry methods, it is applicable to both small inorganic molecules and to VOCs and easily lends itself to quantitative analysis. 2D IR spectroscopy has not been used for trace-gas analysis up to now because of insufficient sensitivity. This project overcomes this problem by building first of its kind cavity-enhanced 2D IR spectrometer, with up to four orders of magnitude better sensitivity than the previous state of the art, and applying it to vibrational spectroscopy of VOCs. The potential for exploitation of the project outcomes includes breath analysis diagnostics, detection of explosives, narcotics and other trace-gas analysis problems. There are also many potential applications of the outcomes in basic science, in the field of ultrafast dynamics of optically dilute samples (e.g. cold molecular jets or sub monolayer films). Two notable examples include the problem of intramolecular vibrational energy redistribution and the dynamics of hydrogen bond networks. The expertise and unique skills gained during the outgoing phase will be used to establish a new research program in the host institution.

This is a project for higher education student and staff mobility between Programme Countries and Partner Countries. Please consult the website of the organisation to obtain additional details.

This is a project for higher education student and staff mobility between Programme Countries and Partner Countries. Please consult the website of the organisation to obtain additional details.

This is a higher education student and staff mobility project, please consult the website of the organisation to obtain additional details.

Due to its simplicity, H2 constitutes a perfect tool for testing fundamental physics: testing quantum electrodynamics, determining fundamental constants, or searching for new physics beyond the Standard Model. H2 has a huge advantage over the other simple calculable systems (such as H, He, or HD+) of having a set of a few hundred ultralong living rovibrational states, which implies the ultimate limit for testing fundamental physics with H2 at a relative accuracy level of 10^-24. The present experiments are far from exploring this huge potential. The main reason for this is that H2 in its ground electronic state extremely weakly interacts with electric and magnetic fields; hence, H2 is not amenable to standard techniques of molecule slowing, cooling, and trapping. In this project, we propose a completely new approach for H2 spectroscopy. For the first time, we will trap a cold sample of H2. We will consider two approaches: superconducting magnetic trap and ultrahigh-power optical dipole trap (with trap depths of the order of 1 mK). T = 5 K will be achieved with a standard refrigeration technique, and the trap will be filled in situ with the 5 K thermal distribution of the H2 sample. Presently, there is no technology available to cool down the H2 gas sample from 5 K to 1 mK; hence, the only option is to directly capture the coldest fraction. The majority of the molecules that initially fill the trap zone will be lost. However, the high initial H2 density will allow us to trap up to 600 000 molecules. We will do infrared-ultraviolet double resonance H2 spectroscopy referenced to the optical frequency comb and primary frequency standard. The ability to do spectroscopy using a cold and trapped sample will eliminate the sources of uncertainty that have limited previous best approaches and will allow us to improve the accuracy by at least two orders of magnitude. The H2 traps will open up a new way for further long-term progress in the metrology of H2 rovibrational lines.