Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Precision Measurements with a Molecular Clock 1 ANDREW

Mickey McDonald, B. H. McGuyer, Geoffrey Z. Iwata, Florian Apfelbeck, Ludwig Maximilian, Marco G. Tarallo

Published Jan 1, 2015• 0 citations
OpenAlex

Abstract

in a lattice. Sr2 has a range of electronically excited bound states which are readily accessible with optical wavelengths using the narrow 1S0->3P1 intercombination line. As in Nat. Phys. 11, 32, we measure the lifetimes of the narrow, deeply-bound subradiant states in the 1g (1S0+3P1 dissociative limit) potential, allowing for coherent control of molecules and a comparison with theoretical predictions of the lifetimes and transition strengths of these states. Next, we study ultracold photodissociation of Sr2 molecules through abortion of one and two photons near the atomic intercombination line. This allows us to observe the vector character of transition elements through the angular dissociation pattern and to directly measure barrier heights in the excited state potentials. Finally, as shown in PRL 114, 023001, we demonstrate that in a non-magic lattice, a narrow transition can be used to measure the trapped gas temperature through the linewidth of the spectral feature corresponding to the carrier transitions. We use this technique to measure the temperature of Sr2 molecules to 10x higher precision than with standard techniques. We discuss future prospects with this molecular lattice clock. 1 Funding from NIST, ARO, and NSF IGERT

Related papers

Ultracold Molecules in Optical Lattices: Efficient Production and Application to Molecular Clocks

Tanya Zelevinsky

Abstract : We have established the strontium molecular clock as the leading ultracold-molecule precision measurement platform. We can fully control the molecules internal and external quantum states, as in state-of-the-art atomic lattice clocks. Using the quantized molecular spectra in an optical lattice, we devised a new lattice thermometry method that is advantageous for many lattice experiments, including clocks and manybody physics studies. The full quantum control allowed us to observe deeply subradiant molecular states, and coherently control them. We measured lifetimes enhanced by up to 300 times. Ultranarrow transitions to these states permitted a rigorous study of asymptotic physics at the atom-molecule threshold. We proved that subradiant states can decay to the ground state via higher-order electromagnetic transitions, with a rate that grows as the square of the bond length, and are quenched by predissociation at a rate proportional to the vibrational level spacing. We introduced a precise technique for measuring molecular binding energies via photofragmentation; controlled forbidden optical transition strengths with weak magnetic fields by five orders of magnitude; and explained anomalously large magnetic susceptibilities of the asymptotic molecules. The unprecedented precision, coupled with advanced ab initio theory, paves the way to exciting new directions for the molecular clock.

•May 3, 2015•0 citations

Quantum Metrology with a Molecular Lattice Clock and State-Selected Photodissociation of Ultracold Molecules

Chih-Hsi Lee

Over the past few decades, rapid development of laser cooling techniques and narrow-linewidth lasers have allowed atom-based quantum clocks to achieve unprecedented precision. Techniques originally developed for atomic clocks can be extended to ultracold molecules, with applications ranging from quantum-state-controlled ultracold chemistry to searches for new physics. Because of the richness of molecular structure, quantum metrology based on molecules provides possibilities for testing physics that is beyond the scope of traditional atomic clocks. This thesis presents the work performed to establish a state-of-the-art quantum clock based on ultracold molecules. The molecular clock is based on a frequency difference between two vibrational levels in the electronic ground state of 88Sr2 diatomic molecules. Such a clock allows us test molecular QED, improve constraints on nanometer-scale gravity, and potentially provide a model-independent test of temporal variations of the proton-electron mass ratio. Trap-insensitive spectroscopy is crucial for extending coherent molecule-light interactions and achieving a high quality factor Q. We have demonstrated a magic wavelength technique for molecules by manipulating the optical lattice frequency near narrow polarizability resonances. This general technique allows us to increase the coherence time to tens of ms, an improvement of a factor of several thousand, and to narrow the linewidth of a 25 THz vibrational transition initially to 30 Hz. This width corresponds to the quality factor Q=8x10^11. Besides the molecular quantum metrology, investigations of novel phenomena in state-selected photodissociation are also described in this thesis, including magnetic-field control of photodissociation and observation of the crossover from ultracold to quasiclassical chemistry.

•Jan 1, 2020•0 citations

Prospects for application of ultracold Sr2 molecules in precision measurements

Svetlana Kotochigova, Tanya Zelevinsky, Jun Ye

Precision measurements with ultracold molecules require development of robust and sensitive techniques to produce and interrogate the molecules. With this goal, we theoretically analyze factors that affect frequency measurements between rovibrational levels of the ${\mathrm{Sr}}_{2}$ molecule in the electronic ground state. This measurement can be used to constrain the possible time variation of the proton-electron mass ratio. ${\mathrm{Sr}}_{2}$ is expected to be a strong candidate for achieving high precision due to the spinless nature and ease of cooling and perturbation-free trapping of Sr [T. Zelevinsky et al., Phys. Rev. Lett. 100, 043201 (2008)]. The analysis includes calculations of two-photon transition dipole moments between deeply and weakly bound vibrational levels, lifetimes of intermediate excited states, and Stark shifts of the vibrational levels by the optical lattice field, including possibilities of Stark-cancellation trapping.

arXiv:0811.3971•Physical Review A•Jan 8, 2009•48 citations

Testing fundamental physics with molecular lattice clocks

Mateusz Borkowski, Emily Tiberi, Brandon Iritani +4 more

Ultracold molecules are a powerful platform for metrology, precision measurements and searches for new, beyond-the-Standard-Model physics. Sr2, thanks to its simple structure, insensitivity to external fields and narrow optical transitions, provides an excellent testbed for the search for new interactions. Here, we present a detailed characterization of our 88Sr2 molecular clock for a vibrational transition spanning the entire depth of the ground state potential. We also discuss prospects to use strontium isotopologues to place improved constraints on new mass-dependent forces, including possible pathways toward the production of ultracold 86Sr2 and 84Sr2 dimers and spectroscopy of clock lines in these species for use in the search for new mass-dependent forces.

Optical and Quantum Sensing and Precision Metrology II•Mar 8, 2023•0 citations

Narrow Line Photoassociation in an Optical Lattice

Tanya Zelevinsky, Martin M. Boyd, Andrew D. Ludlow +5 more

With ultracold 88Sr in a 1D magic wavelength optical lattice, we performed narrow-line photoassociation spectroscopy near the 1S0 - 3P1 intercombination transition. Nine least-bound vibrational molecular levels associated with the long-range 0u and 1u potential energy surfaces were measured and identified. A simple theoretical model accurately describes the level positions and treats the effects of the lattice confinement on the line shapes. The measured resonance strengths show that optical tuning of the ground state scattering length should be possible without significant atom loss.

arXiv:physics/0602135•Physical Review Letters•May 22, 2006•111 citations

PRECISION MEASUREMENT BASED ON ULTRACOLD ATOMS AND COLD MOLECULES

Jun Ye, Sebastian Blatt, Martin M. Boyd +8 more

Ultracold atoms and molecules provide ideal stages for precision tests of fundamental physics. With microkelvin neutral strontium atoms confined in an optical lattice, we have achieved a fractional resolution of 4 × 10-15 on the 1S0–3P0 doubly forbidden 87 Sr clock transition at 698 nm. Measurements of the clock line shifts as a function of experimental parameters indicate systematic errors below the 10-15 level. The ultrahigh spectral resolution permits resolving the nuclear spin states of the clock transition at small magnetic fields, leading to measurements of the 3P0 magnetic moment and metastable lifetime. In addition, photoassociation spectroscopy performed on the narrow 1S0–3P1 transition of 88 Sr shows promise for efficient optical tuning of the ground state scattering length and production of ultracold ground state molecules. Lattice-confined Sr 2 molecules are suitable for constraining the time variation of the proton–electron mass ratio. In a separate experiment, cold, stable, ground state polar molecules are produced from Stark decelerators. These cold samples have enabled an order-of-magnitude improvement in the measurement precision of ground state, Λ doublet microwave transitions in the OH molecule. Comparing the laboratory results to those from OH megamasers in interstellar space will allow a sensitivity of 10-6 for measuring the potential time variation of the fundamental fine structure constant Δα/α over 1010 years. These results have also led to improved understandings of the molecular structure. The study of the low magnetic field behavior of OH in its 2Π3/2 ro-vibronic ground state precisely determines a differential Landé g factor between opposite parity components of the Λ doublet.

International Journal of Modern Physics D•Dec 1, 2007•21 citations
in a lattice. Sr2 has a range of electronically excited bound states which are readily accessible with optical wavelengths using the narrow 1S0->3P1 intercombination line. As in Nat. Phys. 11, 32, we measure the lifetimes of the narrow, deeply-bound subradiant states in the 1g (1S0+3P1 dissociative limit) potential, allowing for coherent control of molecules and a comparison with theoretical predictions of the lifetimes and transition strengths of these states. Next, we study ultracold photodissociation of Sr2 molecules through abortion of one and two photons near the atomic intercombination line. This allows us to observe the vector character of transition elements through the angular dissociation pattern and to directly measure barrier heights in the excited state potentials. Finally, as shown in PRL 114, 023001, we demonstrate that in a non-magic lattice, a narrow transition can be used to measure the trapped gas temperature through the linewidth of the spectral feature corresponding to the carrier transitions. We use this technique to measure the temperature of Sr2 molecules to 10x higher precision than with standard techniques. We discuss future prospects with this molecular lattice clock. 1 Funding from NIST, ARO, and NSF IGERT
Abstract : We have established the strontium molecular clock as the leading ultracold-molecule precision measurement platform. We can fully control the molecules internal and external quantum states, as in state-of-the-art atomic lattice clocks. Using the quantized molecular spectra in an optical lattice, we devised a new lattice thermometry method that is advantageous for many lattice experiments, including clocks and manybody physics studies. The full quantum control allowed us to observe deeply subradiant molecular states, and coherently control them. We measured lifetimes enhanced by up to 300 times. Ultranarrow transitions to these states permitted a rigorous study of asymptotic physics at the atom-molecule threshold. We proved that subradiant states can decay to the ground state via higher-order electromagnetic transitions, with a rate that grows as the square of the bond length, and are quenched by predissociation at a rate proportional to the vibrational level spacing. We introduced a precise technique for measuring molecular binding energies via photofragmentation; controlled forbidden optical transition strengths with weak magnetic fields by five orders of magnitude; and explained anomalously large magnetic susceptibilities of the asymptotic molecules. The unprecedented precision, coupled with advanced ab initio theory, paves the way to exciting new directions for the molecular clock.
Over the past few decades, rapid development of laser cooling techniques and narrow-linewidth lasers have allowed atom-based quantum clocks to achieve unprecedented precision. Techniques originally developed for atomic clocks can be extended to ultracold molecules, with applications ranging from quantum-state-controlled ultracold chemistry to searches for new physics. Because of the richness of molecular structure, quantum metrology based on molecules provides possibilities for testing physics that is beyond the scope of traditional atomic clocks. This thesis presents the work performed to establish a state-of-the-art quantum clock based on ultracold molecules. The molecular clock is based on a frequency difference between two vibrational levels in the electronic ground state of 88Sr2 diatomic molecules. Such a clock allows us test molecular QED, improve constraints on nanometer-scale gravity, and potentially provide a model-independent test of temporal variations of the proton-electron mass ratio. Trap-insensitive spectroscopy is crucial for extending coherent molecule-light interactions and achieving a high quality factor Q. We have demonstrated a magic wavelength technique for molecules by manipulating the optical lattice frequency near narrow polarizability resonances. This general technique allows us to increase the coherence time to tens of ms, an improvement of a factor of several thousand, and to narrow the linewidth of a 25 THz vibrational transition initially to 30 Hz. This width corresponds to the quality factor Q=8x10^11. Besides the molecular quantum metrology, investigations of novel phenomena in state-selected photodissociation are also described in this thesis, including magnetic-field control of photodissociation and observation of the crossover from ultracold to quasiclassical chemistry.
Precision measurements with ultracold molecules require development of robust and sensitive techniques to produce and interrogate the molecules. With this goal, we theoretically analyze factors that affect frequency measurements between rovibrational levels of the Sr2{\mathrm{Sr}}_{2}Sr2​ molecule in the electronic ground state. This measurement can be used to constrain the possible time variation of the proton-electron mass ratio. Sr2{\mathrm{Sr}}_{2}Sr2​ is expected to be a strong candidate for achieving high precision due to the spinless nature and ease of cooling and perturbation-free trapping of Sr [T. Zelevinsky et al., Phys. Rev. Lett. 100, 043201 (2008)]. The analysis includes calculations of two-photon transition dipole moments between deeply and weakly bound vibrational levels, lifetimes of intermediate excited states, and Stark shifts of the vibrational levels by the optical lattice field, including possibilities of Stark-cancellation trapping.
Ultracold molecules are a powerful platform for metrology, precision measurements and searches for new, beyond-the-Standard-Model physics. Sr2, thanks to its simple structure, insensitivity to external fields and narrow optical transitions, provides an excellent testbed for the search for new interactions. Here, we present a detailed characterization of our 88Sr2 molecular clock for a vibrational transition spanning the entire depth of the ground state potential. We also discuss prospects to use strontium isotopologues to place improved constraints on new mass-dependent forces, including possible pathways toward the production of ultracold 86Sr2 and 84Sr2 dimers and spectroscopy of clock lines in these species for use in the search for new mass-dependent forces.
With ultracold 88Sr in a 1D magic wavelength optical lattice, we performed narrow-line photoassociation spectroscopy near the 1S0 - 3P1 intercombination transition. Nine least-bound vibrational molecular levels associated with the long-range 0u and 1u potential energy surfaces were measured and identified. A simple theoretical model accurately describes the level positions and treats the effects of the lattice confinement on the line shapes. The measured resonance strengths show that optical tuning of the ground state scattering length should be possible without significant atom loss.
Ultracold atoms and molecules provide ideal stages for precision tests of fundamental physics. With microkelvin neutral strontium atoms confined in an optical lattice, we have achieved a fractional resolution of 4 × 10-15 on the 1S0–3P0 doubly forbidden 87 Sr clock transition at 698 nm. Measurements of the clock line shifts as a function of experimental parameters indicate systematic errors below the 10-15 level. The ultrahigh spectral resolution permits resolving the nuclear spin states of the clock transition at small magnetic fields, leading to measurements of the 3P0 magnetic moment and metastable lifetime. In addition, photoassociation spectroscopy performed on the narrow 1S0–3P1 transition of 88 Sr shows promise for efficient optical tuning of the ground state scattering length and production of ultracold ground state molecules. Lattice-confined Sr 2 molecules are suitable for constraining the time variation of the proton–electron mass ratio. In a separate experiment, cold, stable, ground state polar molecules are produced from Stark decelerators. These cold samples have enabled an order-of-magnitude improvement in the measurement precision of ground state, Λ doublet microwave transitions in the OH molecule. Comparing the laboratory results to those from OH megamasers in interstellar space will allow a sensitivity of 10-6 for measuring the potential time variation of the fundamental fine structure constant Δα/α over 1010 years. These results have also led to improved understandings of the molecular structure. The study of the low magnetic field behavior of OH in its 2Π3/2 ro-vibronic ground state precisely determines a differential Landé g factor between opposite parity components of the Λ doublet.