## Files in this item

FilesDescriptionFormat

application/vnd.openxmlformats-officedocument.presentationml.presentation

RH04_Presentation.pptx (1MB)
PresentationMicrosoft PowerPoint 2007

application/pdf

RH04_Abstract.pdf (24kB)
AbstractPDF

text/plain

RH04_Abstract.txt (2kB)
AbstractText file

## Description

 Title: Mm-wave Spectroscopy And Determination Of The Radiative Branching Ratios Of 11bh For Laser Cooling Experiments Author(s): Truppe, Stefan Contributor(s): Tarbutt, Michael; Hinds, Ed; Hendricks, Richard James; Holland, Darren Subject(s): Cold/Ultra-cold/Physics Abstract: We aim to slow a supersonic, molecular beam of $^{11}$BH using a Zeeman slower and subsequently cool the molecules to sub-millikelvin temperatures in a magneto-optical trap. Most molecules are not suitable for direct laser cooling because the presence of rotational and vibrational degrees of freedom means there is no closed-cycle transition which is necessary to scatter a large number of photons. As was pointed out by Di~Rosa\footnote{M.~D.~Di~Rosa, \textit{The European Physical Journal D}~\underline{\textbf{31}}, 395, 2004} there exists a class of molecules for which the excitation of vibrational modes is suppressed due to highly diagonal Franck-Condon factors. Furthermore, Stuhl et al.\footnote{B.~K.~Stuhl et al., \textit{Physical Review Letters}~\underline{\textbf{101}}, 243002, 2008} showed that angular momentum selection rules can be used to suppress leakage to undesired rotational states. Here we present a measurement of the radiative branching ratios of the $A^1\Pi\rightarrow X^1\Sigma$ transition in $^{11}$BH - a necessary step towards subsequent laser cooling experiments. We also perform high-resolution mm-wave spectroscopy of the $J'=1\leftarrow J=0$ rotational transition in the $X^1\Sigma (v=0)$ state near 708~GHz. From this measurement we derive new, accurate hyper fine constants and compare these to theoretical descriptions. The measured branching ratios suggest that it is possible to laser cool $^{11}$BH molecules close to the recoil temperature of 4~$\mu$K using three laser frequencies only. Issue Date: 2014-06-19 Publisher: International Symposium on Molecular Spectroscopy Citation Info: Truppe, S.; Tarbutt, M.; Hinds, E.; Hendricks, R.J.; Holland, D. MM-WAVE SPECTROSCOPY AND DETERMINATION OF THE RADIATIVE BRANCHING RATIOS OF 11BH FOR LASER COOLING EXPERIMENTS. Proceedings of the International Symposium on Molecular Spectroscopy, Urbana, IL, June 16-21, 2014. DOI: 10.15278/isms.2014.RH04 Genre: CONFERENCE PAPER/PRESENTATION Type: Text Language: English URI: http://hdl.handle.net/2142/50827 DOI: 10.15278/isms.2014.RH04 Rights Information: Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/ Date Available in IDEALS: 2014-09-172015-04-14
﻿