arXiv subjects

Michael Bellos

Publications and source records attributed to Michael Bellos.

4 recordsLinked to original sources

arXiv2014

Production of rovibronic ground state RbCs molecules via two-photon cascade decay

We report the production of ultracold RbCs molecules in the rovibronic ground state, i.e., $X^1Σ^+ (v=0, J=0)$, by short-range photoassociation to the $2^3Π_{0}$ state followed by spontaneous emission. We use narrowband depletion spectroscopy to probe the distribution of rotational levels formed in the $X ^1Σ^+(v=0)$ state. We conclude, based on selection rules, that the primary decay route to $X ^1Σ^+(v=0)$ is a two-step cascade decay that leads to as much as $33\%$ branching into the $J=0$ rotational level. The experimental simplicity of our scheme opens up the possibility of easier access to the study and manipulation of ultracold heteronuclear molecules in the rovibronic ground state.

physics.atom-ph↗

arXiv2013

Spectroscopy of the Double Minimum $3\,^3 Π_Ω$ Electronic State of $^{39}$K$^{85}$Rb

We report the observation and analysis of the $3\,^3Π_Ω$ double-minimum electronic excited state of $^{39}$K$^{85}$Rb. The spin-orbit components ($0^{+}, 0^{-}, 1$ and 2) of this state are investigated based on potentials developed from the available \emph{ab initio} potential curves. We have assigned the vibrational levels $v'=2-11$ of the $3\,^3Π_{1,2}$ potentials and $v'=2-12$ of the $3\,^3Π_{0^{+/-}}$ potential. We compare our experimental observations of the $3\,^3Π_Ω$ state with predictions based on theoretical potentials. The observations are based on resonance enhanced multiphoton ionization (REMPI) of ultracold KRb in vibrational levels $v"=14-25$ of the $a\,^3Σ^+$ state. These \emph{a}-state ultracold molecules are formed by photoassociation of ultracold $^{39}$K and $^{85}$Rb atoms to the 5(1) state of KRb followed by spontaneous emission to the \emph{a} state.

physics.atom-ph↗

arXiv2012

Direct Photoassociative Formation of Ultracold KRb Molecules in the Lowest Vibrational Levels of the Ground State

We report continuous direct photoassociative formation of ultracold KRb molecules in the lowest vibrational levels $(v"=0 -10)$ of the electronic ground state $(X ^1Σ^+)$, starting from $^{39}$K and $^{85}$Rb atoms in a magneto-optical trap. The process exploits a newfound resonant coupling between the $2(1), v'=165$ and $4(1), v'=61$ levels, which exhibit an almost equal admixture of the uncoupled eigenstates. The production rate of the $X^1Σ^+$ ($v"$=0) level is estimated to be $5\times10^3$ molecules/sec.

physics.atom-ph↗

arXiv2005

Low-Energy Deuteron Polarimeter

We built a Low Energy Deuteron Polarimeter which measures the spin-polarization of deuteron beams in the energy range of 25 to 80 keV. This polarimeter works by measuring azimuthal asymmetries in the D(\vec d, n)^{3}He reaction and comparing them to known analyzing powers. We built this polarimeter to test its performance and to cross-check other existing polarimeters at KVI. We were able to use this polarimeter as a vector polarimeter, but not as a tensor polarimeter because of an uncertain 'tensor analyzing power' calibration.

nucl-ex↗