A combination of the pump-probe technique and Coulomb explosion imaging is used to image the time resolved response of the 4He trimer to the perturbation by a femtosecond laser pulse. In the experiment, the interaction of the helium trimer with a non-ionizing pump-pulse is imaged by an ionizing probe pulse. The momenta, which the charged trimer fragments gain in the Coulomb explosion triggered by the probe pulse, are measured by a COLTRIMS reaction microscope. The response of the helium trimer is first analysed in momentum space. Subsequently, a reconstruction algorithm is used, in order to obtain the structural information about detected trimers from the momenta of the trimer fragments. This allows to analyse the response of the helium trimer in position space. The experiment is primarily motivated by the question, whether a laser pulse can excite the trimer ground state to the Efimov state, which is a huge quantum halo. Although a population of the Efimov state is not observed, in the experiment, the recorded data show the population of an unknown state, which could not yet be identified. Further, the response of the helium trimer shows an alignment wave, which might arise from the interference of two quantum states.A combination of the pump-probe technique and Coulomb explosion imaging is used to image the time resolved response of the 4He trimer to the perturbation by a femtosecond laser pulse. In the experiment, the interaction of the helium trimer with a non-ionizing pump-pulse is imaged by an ionizing probe pulse. The momenta, which the charged trimer fragments gain in the Coulomb explosion triggered by the probe pulse, are measured by a COLTRIMS reaction microscope. The response of the helium trimer is first analysed in momentum space. Subsequently, a reconstruction algorithm is used, in order to obtain the structural information about detected trimers from the momenta of the trimer fragments. This allows to analyse the response of the helium trimer in position space. The experiment is primarily motivated by the question, whether a laser pulse can excite the trimer ground state to the Efimov state, which is a huge quantum halo. Although a population of the Efimov state is not observed, in the experiment, the recorded data show the population of an unknown state, which could not yet be identified. Further, the response of the helium trimer shows an alignment wave, which might arise from the interference of two quantum states.

Jan 1, 20210 citations

Analytic representation of the Efimov effect in the helium trimer

LAWRENCE L. JUN. LOHR, S. M. Blinder

Exact solutions for the low-temperature helium dimer and trimer, $^{4}\mathrm{He}_{2}$ and $^{4}\mathrm{He}_{3}$ , are derived, based on our $\ensuremath{\delta}$ function model for the interatomic potential. For the trimer, the Faddeev equations are shown to be separable in hyperspherical coordinates, with the $S$ -wave alone giving an exact solution. The parameters ${\ensuremath{\lambda}}_{0}$ and ${r}_{0}$ are fitted to accurate computations on the dimer and trimer. Excited states of the trimer are shown to exhibit the Efimov effect, whereby artificially reducing the strength of the two-body potential causes an infinite number of weakly-bound levels to condense out of the continuum. All the features anticipated by Efimov are quantitatively reproduced within our model. Since short-range details of the intermolecular forces are not relevant, our results can be considered to be universally applicable.Exact solutions for the low-temperature helium dimer and trimer, $^{4}\mathrm{He}_{2}$ and $^{4}\mathrm{He}_{3}$, are derived, based on our $\ensuremath{\delta}$ function model for the interatomic potential. For the trimer, the Faddeev equations are shown to be separable in hyperspherical coordinates, with the $S$-wave alone giving an exact solution. The parameters ${\ensuremath{\lambda}}_{0}$ and ${r}_{0}$ are fitted to accurate computations on the dimer and trimer. Excited states of the trimer are shown to exhibit the Efimov effect, whereby artificially reducing the strength of the two-body potential causes an infinite number of weakly-bound levels to condense out of the continuum. All the features anticipated by Efimov are quantitatively reproduced within our model. Since short-range details of the intermolecular forces are not relevant, our results can be considered to be universally applicable.

Physical Review AJun 2, 20045 citations

Quantum algorithms with tensor approach

Lejia Gu

Jan 1, 20200 citations

The helium trimer has no bound rotational excited states

Teck-Ghee Lee, Brett D. Esry, Bingcong Gou +1 more

We have searched for bound states of helium trimers with nonzero angular momenta. Including only pair interactions between helium atoms, we solved the Schrödinger equation in hyperspherical coordinates in the adiabatic approximation. From the resulting potential curves - which are mostly repulsive for nonzero angular momenta - we conclude that there are no bound rotational excited states in any of the isotopes of the helium trimer. The symmetry properties of the trimer wavefunctions in the body-fixed frame are also analysed.We have searched for bound states of helium trimers with nonzero angular momenta. Including only pair interactions between helium atoms, we solved the Schrödinger equation in hyperspherical coordinates in the adiabatic approximation. From the resulting potential curves - which are mostly repulsive for nonzero angular momenta - we conclude that there are no bound rotational excited states in any of the isotopes of the helium trimer. The symmetry properties of the trimer wavefunctions in the body-fixed frame are also analysed.

Journal of Physics B Atomic Molecular and Optical PhysicsMar 22, 200121 citations

Tensor projection mechanism and algorithm implementation

Fei Wang, Wang Zhan-chang, Xiang Li +1 more

Applied IntelligenceMar 26, 20210 citations

Exact solutions for the low-temperature helium dimer and trimer,

^{4}\mathrm{He}_{2}

and

^{4}\mathrm{He}_{3}

, are derived, based on our $\ensuremath{\delta}$ function model for the interatomic potential. For the trimer, the Faddeev equations are shown to be separable in hyperspherical coordinates, with the

S

-wave alone giving an exact solution. The parameters ${\ensuremath{\lambda}}_{0}$ and

{r}_{0}

are fitted to accurate computations on the dimer and trimer. Excited states of the trimer are shown to exhibit the Efimov effect, whereby artificially reducing the strength of the two-body potential causes an infinite number of weakly-bound levels to condense out of the continuum. All the features anticipated by Efimov are quantitatively reproduced within our model. Since short-range details of the intermolecular forces are not relevant, our results can be considered to be universally applicable.