Photon emission spectroscopy of ion-atom collisions

The possibility of optical target preparation has added new dimensions to atomic collision spectroscopy. By suitable choices of photon wavelength and polarization, the shape and dynamics of the target atom can be controlled and manipulated before the interaction with the projectile. Similarly, the shape and dynamics of the atomic states in the exit channel can be monitored by polarization analysis of the photons emitted in the subsequent optical decay. Finally, the target temperature may be strongly reduced by laser cooling and used for recoil ion momentum spectroscopy. A series of simple examples are presented in order to demonstrate the kind of insight into the interaction dynamics that may be gleaned from combined experimental and theoretical studies of this kind.The possibility of optical target preparation has added new dimensions to atomic collision spectroscopy. By suitable choices of photon wavelength and polarization, the shape and dynamics of the target atom can be controlled and manipulated before the interaction with the projectile. Similarly, the shape and dynamics of the atomic states in the exit channel can be monitored by polarization analysis of the photons emitted in the subsequent optical decay. Finally, the target temperature may be strongly reduced by laser cooling and used for recoil ion momentum spectroscopy. A series of simple examples are presented in order to demonstrate the kind of insight into the interaction dynamics that may be gleaned from combined experimental and theoretical studies of this kind.

Physica ScriptaJan 1, 20010 citations

Unresolved sideband photon recoil spectroscopy of molecular ions

Emilie Hindbo Clausen, Vincent Jarlaud, Karin Fisher +3 more

We reflect on the prospect of exploiting the recoil associated with absorption and emission of photons to perform spectroscopy of a single molecular ion. For this recoil to be detectable, the molecular ion is sympathetically cooled by a laser-cooled atomic ion to near their common quantum-mechanical ground state within a trapping potential. More specifically, we present a general framework for simulating the expected photon recoil spectra in regimes where either the natural transition linewidth ${\mathrm{\ensuremath{\Gamma}}}_{t}$ of the molecular ion or the spectral width ${\mathrm{\ensuremath{\Gamma}}}_{L}$ of the exciting light source exceeds the motional frequencies of the two-ion system. To exemplify the framework, we present two complementary cases: spectroscopy of the broad $3\mathrm{s} ^{2}\mathrm{S}_{1/2}\ensuremath{-}3\mathrm{p} ^{2}\mathrm{P}_{3/2}$ electronic transition (${\mathrm{\ensuremath{\Gamma}}}_{t}/2\ensuremath{\pi}=41.8\phantom{\rule{0.16em}{0ex}}\mathrm{M}\mathrm{Hz}$) of a single $^{24}\mathrm{Mg}^{+}$ ion at $\ensuremath{\lambda}=279.6$ nm by a narrow laser source $({\mathrm{\ensuremath{\Gamma}}}_{L}/2\ensuremath{\pi}\ensuremath{\lesssim}1\phantom{\rule{0.16em}{0ex}}\mathrm{MHz})$ and mid-infrared vibrational spectroscopy of the very narrow $|v=0,J=1\ensuremath{\rangle}\ensuremath{-}|{v}^{\ensuremath{'}}=1,{J}^{\ensuremath{'}}=0\ensuremath{\rangle}$ transition $({\mathrm{\ensuremath{\Gamma}}}_{t}/2\ensuremath{\pi}=2.50\phantom{\rule{0.16em}{0ex}}\mathrm{Hz})$ at $\ensuremath{\lambda}=6.17\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$ in the $^{1}\mathrm{\ensuremath{\Sigma}}^{+}$ electronic ground state of $^{24}\mathrm{MgH}^{+}$ by a broadband laser source $({\mathrm{\ensuremath{\Gamma}}}_{L}/2\ensuremath{\pi}\ensuremath{\gtrsim}50\phantom{\rule{0.16em}{0ex}}\mathrm{MHz})$. The atomic ion $^{24}\mathrm{Mg}^{+}$ has been picked to introduce a simple system to make comparisons with experimental results while still capturing most of the physics involved in electronic excitations of molecular ions.We reflect on the prospect of exploiting the recoil associated with absorption and emission of photons to perform spectroscopy of a single molecular ion. For this recoil to be detectable, the molecular ion is sympathetically cooled by a laser-cooled atomic ion to near their common quantum-mechanical ground state within a trapping potential. More specifically, we present a general framework for simulating the expected photon recoil spectra in regimes where either the natural transition linewidth ${\mathrm{\ensuremath{\Gamma}}}_{t}$ of the molecular ion or the spectral width ${\mathrm{\ensuremath{\Gamma}}}_{L}$ of the exciting light source exceeds the motional frequencies of the two-ion system. To exemplify the framework, we present two complementary cases: spectroscopy of the broad $3\mathrm{s} ^{2}\mathrm{S}_{1/2}\ensuremath{-}3\mathrm{p} ^{2}\mathrm{P}_{3/2}$ electronic transition (${\mathrm{\ensuremath{\Gamma}}}_{t}/2\ensuremath{\pi}=41.8\phantom{\rule{0.16em}{0ex}}\mathrm{M}\mathrm{Hz}$) of a single $^{24}\mathrm{Mg}^{+}$ ion at $\ensuremath{\lambda}=279.6$ nm by a narrow laser source $({\mathrm{\ensuremath{\Gamma}}}_{L}/2\ensuremath{\pi}\ensuremath{\lesssim}1\phantom{\rule{0.16em}{0ex}}\mathrm{MHz})$ and mid-infrared vibrational spectroscopy of the very narrow $|v=0,J=1\ensuremath{\rangle}\ensuremath{-}|{v}^{\ensuremath{'}}=1,{J}^{\ensuremath{'}}=0\ensuremath{\rangle}$ transition $({\mathrm{\ensuremath{\Gamma}}}_{t}/2\ensuremath{\pi}=2.50\phantom{\rule{0.16em}{0ex}}\mathrm{Hz})$ at $\ensuremath{\lambda}=6.17\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$ in the $^{1}\mathrm{\ensuremath{\Sigma}}^{+}$ electronic ground state of $^{24}\mathrm{MgH}^{+}$ by a broadband laser source $({\mathrm{\ensuremath{\Gamma}}}_{L}/2\ensuremath{\pi}\ensuremath{\gtrsim}50\phantom{\rule{0.16em}{0ex}}\mathrm{MHz})$. The atomic ion $^{24}\mathrm{Mg}^{+}$ has been picked to introduce a simple system to make comparisons with experimental results while still capturing most of the physics involved in electronic excitations of molecular ions.

arXiv:2004.02959Physical Review AJun 9, 20224 citations

Collisional Spectroscopy of Laser Excited Atoms

M. Allegrini

NATO ASI series. Series B : PhysicsJan 1, 19850 citations

Collisions of Highly Excited Atoms

R. F. Stebbings

Advances in atomic and molecular physicsJan 1, 19798 citations

Spectroscopy of atomic and molecular ions using quantum logic

Piet O. Schmidt, Till Rosenband, Jeroen C. J. Koelemeij +4 more

Recently developed techniques for quantum computation using trapped ions allow precise coherent control of the internal and external states of single atoms. Here we report how these techniques can be employed to perform precision spectroscopy of atomic and molecular ions that lack accessible transitions for laser cooling and detection. Furthermore, we discuss how quantum logic can be used to laser‐cool molecules to near their rotational and vibrational ground state by avoiding detrimental spontaneous emission of photons from the molecule.Recently developed techniques for quantum computation using trapped ions allow precise coherent control of the internal and external states of single atoms. Here we report how these techniques can be employed to perform precision spectroscopy of atomic and molecular ions that lack accessible transitions for laser cooling and detection. Furthermore, we discuss how quantum logic can be used to laser‐cool molecules to near their rotational and vibrational ground state by avoiding detrimental spontaneous emission of photons from the molecule.

AIP conference proceedingsJan 1, 200620 citations

^{24}\mathrm{Mg}^{+}

ion at $\ensuremath{\lambda}=279.6$ nm by a narrow laser source $({\mathrm{\ensuremath{\Gamma}}}_{L}/2\ensuremath{\pi}\ensuremath{\lesssim}1\phantom{\rule{0.16em}{0ex}}\mathrm{MHz})$ and mid-infrared vibrational spectroscopy of the very narrow $|v=0,J=1\ensuremath{\rangle}\ensuremath{-}|{v}^{\ensuremath{'}}=1,{J}^{\ensuremath{'}}=0\ensuremath{\rangle}$ transition $({\mathrm{\ensuremath{\Gamma}}}_{t}/2\ensuremath{\pi}=2.50\phantom{\rule{0.16em}{0ex}}\mathrm{Hz})$ at $\ensuremath{\lambda}=6.17\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{m}$ in the $^{1}\mathrm{\ensuremath{\Sigma}}^{+}$ electronic ground state of

^{24}\mathrm{MgH}^{+}

by a broadband laser source $({\mathrm{\ensuremath{\Gamma}}}_{L}/2\ensuremath{\pi}\ensuremath{\gtrsim}50\phantom{\rule{0.16em}{0ex}}\mathrm{MHz})$. The atomic ion

^{24}\mathrm{Mg}^{+}

has been picked to introduce a simple system to make comparisons with experimental results while still capturing most of the physics involved in electronic excitations of molecular ions.