We demonstrate cryogenic buffer-gas cooling of gas-phase methyltrioxorhenium (MTO). This molecule is closely related to chiral organometallic molecules where the parity-violating energy differences ...between enantiomers may be measurable. The molecules are produced with a rotational temperature of approximately 6~K by laser ablation of an MTO pellet inside a cryogenic helium buffer gas cell. Facilitated by the low temperature, we demonstrate absorption spectroscopy of the 10.2~\(\mu\)m antisymmetric Re=O stretching mode of MTO with a resolution of 8~MHz and a frequency accuracy of 30~MHz. We partially resolve the hyperfine structure and measure the nuclear quadrupole coupling of the excited vibrational state.
Atomic Physics 20, pp. 44-52 (2006) We present progress towards a new measurement of the electron electric dipole
moment using a cold supersonic beam of YbF molecules. Data are currently being
taken ...with a sensitivity of $10^{-27}\textrm{e.cm}/\sqrt{\textrm{day}}$. We
therefore expect to make an improvement over the Tl experiment of Commins'
group, which currently gives the most precise result. We discuss the systematic
and statistical errors and comment on the future prospect of making a
measurement at the level of $10^{-29}\textrm{e.cm}/\sqrt{\textrm{day}}$.
J. Chem. Phys. 123, 231101 (2005) We have measured the Stark shift of the $A^2\Pi_{1/2} - X^2\Sigma^+$
transition in YbF. We use a molecular beam triple resonance method, with two
laser transitions ...acting as pump and probe, assisted by an rf transition that
tags a single hyperfine transition of the X state. After subtracting the known
ground state Stark shift, we obtain a value of $70.3(1.5) $Hz/(V/cm)$^2$ for
the static electric polarizability of the state $A^2\Pi_{1/2}(J=1/2,f)$. From
this we calculate a value $\mu_e=2.46(3)$D for the electric dipole moment of
the $A^2\Pi_{1/2}(v=0)$ state.
J. Chem. Phys. 126, 124314 (2007) We have developed a source of cold LiH molecules for Stark deceleration and
trapping experiments. Lithium metal is ablated from a solid target into a
supersonically ...expanding carrier gas. The translational, rotational and
vibrational temperatures are 0.9(0.1) K, 5.9(0.5) K and 468(17) K respectively.
Although they have not reached thermal equilibrium with the carrier gas, we
estimate that 90% of the LiH molecules are in the ground state, X^{1}
\Sigma^{+} (v=0, J=0). With a single 7 ns ablation pulse, the number of
molecules in the ground state is 4.5(1.8)*10^{7} molecules per steradian. A
second, delayed, ablation pulse produces another LiH beam in a different part
of the same gas pulse, thereby almost doubling the signal. A long pulse,
lasting 150 microseconds, can make the beam up to 15 times more intense.
J. Phys. B: At. Mol. Opt. Phys. 39 (2006) R263-R291 Beams of polar molecules can be focused using an array of electrostatic
lenses in alternating gradient (AG) configuration. They can also be ...accelerated
or decelerated by applying an appropriate high voltage switching sequence to
the lenses. AG focusing is applicable to molecules in both low-field and
high-field-seeking states and is particularly well suited to the problem of
decelerating heavy molecules and those in their ground rotational state. We
describe the principles of AG deceleration and set out criteria to be followed
in decelerator design, construction and operation. We calculate the
longitudinal and transverse focusing properties of a decelerator, and exemplify
this by 2D-imaging studies of a decelerated beam of metastable CO molecules.
Beams of polar molecules can be focused using an array of electrostatic lenses in alternating gradient (AG) configuration. They can also be accelerated or decelerated by applying an appropriate high ...voltage switching sequence to the lenses. AG focusing is applicable to molecules in both low-field and high-field-seeking states and is particularly well suited to the problem of decelerating heavy molecules and those in their ground rotational state. We describe the principles of AG deceleration and set out criteria to be followed in decelerator design, construction and operation. We calculate the longitudinal and transverse focusing properties of a decelerator, and exemplify this by 2D-imaging studies of a decelerated beam of metastable CO molecules.
We present our progress towards a new measurement of the electron electric
dipole moment using a beam of YbF molecules. Data are currently being taken
with a sensitivity of 10^{-27} e.cm / \sqrt{day}.
We present progress towards a new measurement of the electron electric dipole moment using a cold supersonic beam of YbF molecules. Data are currently being taken with a sensitivity of ...\(10^{-27}\textrm{e.cm}/\sqrt{\textrm{day}}\). We therefore expect to make an improvement over the Tl experiment of Commins' group, which currently gives the most precise result. We discuss the systematic and statistical errors and comment on the future prospect of making a measurement at the level of \(10^{-29}\textrm{e.cm}/\sqrt{\textrm{day}}\).
Phys.Rev.Lett.89:023003,2002 The most sensitive measurements of the electron electric dipole moment d_e
have previously been made using heavy atoms. Heavy polar molecules offer a
greater sensitivity ...to d_e because the interaction energy to be measured is
typically 10^3 times larger than in a heavy atom. We report the first
measurement of this kind, for which we have used the molecule YbF. Together,
the large interaction energy and the strong tensor polarizability of the
molecule make our experiment essentially free of the systematic errors that
currently limit d_e measurements in atoms. Our first result d_e = (- 0.2 \pm
3.2) x 10^-26 e.cm is less sensitive than the best atom measurement, but is
limited only by counting statistics and demonstrates the power of the method.
We have measured the Stark shift of the \(A^2\Pi_{1/2} - X^2\Sigma^+\) transition in YbF. We use a molecular beam triple resonance method, with two laser transitions acting as pump and probe, ...assisted by an rf transition that tags a single hyperfine transition of the X state. After subtracting the known ground state Stark shift, we obtain a value of \(70.3(1.5) \)Hz/(V/cm)\(^2\) for the static electric polarizability of the state \(A^2\Pi_{1/2}(J=1/2,f)\). From this we calculate a value \(\mu_e=2.46(3)\)D for the electric dipole moment of the \(A^2\Pi_{1/2}(v=0)\) state.
