Hasil untuk "physics.atom-ph"

Egor Kovlakov, Rene Gerritsma

We demonstrate precision laser spectroscopy of a trapped $^{173}$Yb$^+$ ion that is not directly laser cooled by coupling it to ultracold atoms. The atomic bath continuously cools the internal degrees of freedom of the ion to its hyperfine ground state via spin-exchange collisions. Successful laser excitation is detected via state-selective charge transfer and subsequent ion loss. We probe the $6^2S_{1/2}\rightarrow 6^2P_{3/2}$ transition at 329 nm and measure the magnetic and electric hyperfine interaction constants for the $6^2P_{3/2}$ state to be $A=-241(1)$ MHz and $B=1460(8)$ MHz, respectively. Our results are in agreement with a previous measurement obtained in a hollow-cathode discharge experiment but are a factor of 6-9 more precise. The techniques demonstrated in this work may be extended to perform precision spectroscopy on other ions with complex level structures.

C. Orchard, J. Kentish

Matthieu Génévriez, Maxence Jungers, Christian Rosen et al.

We investigated resonant multiphoton excitation of high-angular-momentum planetary states of the strontium atom, a quasi-three-body Coulomb system, both experimentally and theoretically. A series of highly doubly excited electronic states converging to the double ionization threshold was identified and reproduced by first-principles calculations, which provided access to the two-electron wavefunctions of the resonances. In these states, the outer electron is dynamically localized at large distances by pendulum-like oscillations of the inner electron across the nucleus. A complementary simple molecular-like adiabatic model offers a clear interpretation of the correlated two-electron motion and suggests that the series is a general feature of highly doubly excited states of atoms and molecules.

Marec W. Heger, Daniel M. Reich

In photoelectron circular dichroism (PECD) it is generally difficult to trace how and when the chirality of the molecule is imprinted onto the photoelectron. We present simulations of PECD in a simple model and employ chirality measures to establish a quantitative connection between the chirality of the potential, the electronic wave function's chirality, and the anisotropy of the photoelectron distribution. We show that these measures are suitable indicators for chirality, paving the way for tracking the chiral evolution from the nuclear scaffold to the final observable.

Sreya Banerjee, Zoltán Harman

Self-energy corrections to the energy levels of bound electrons are calculated in the framework of path integrals. We arrive at the full fermion propagator, using methods of functional integrals, in the form of Schwinger-Dyson equation (SDE). From the full fermion SDE, the self-energy corrected propagator is identified and the energy shift is obtained from the poles of the spectral function. The numerical calculations are performed using complex contour integrals and the B-spline representation of basis functions. We identify ions with Lamb shifts observable via modern mass spectrometric methods.

John L. Bohn, Reuben R. W. Wang

The probability distribution of the real and imaginary parts of atomic scattering lengths $a$ are derived, in a two-channel model that allows for inelastic scattering to occur. While the real part of $a$ remains Cauchy-distributed, as predicted for single channel scattering in the classic work of Gribakin and Flambaum, the imaginary part of $a$ is seen to be strongly peaked near zero. Two-body inelastic scattering rates may therefore be smaller in general than a naive estimate would suggest.

Petr A. Krachkov, Roman N. Lee

We derive an analytical expression for the contribution of the order $mα^2 (Zα)^6$ to the hydrogen Lamb shift which comes from the diagrams for radiative corrections to the Wichmann-Kroll potential. We use modern methods of multiloop calculations, based on IBP reduction, DRA method and differential equations.

D. Nordstrom, C. Alpers

K. Ulbrich, V. Šubr

S. Angelos, Yingwei Yang, K. Patel et al.

A. Degen, M. Kosec

K. Straub, M. Benz, B. Schink

P. Snee, R. C. Somers, Gautham P Nair et al.

Hannah Lomas, I. Cantón, S. MacNeil et al.

R. Buck, S. Rondinini, A. Covington et al.

A. Aggeli, M. Bell, L. Carrick et al.

Yan-Li Zhao, Zongxi Li, Sanaz Kabehie et al.

N. Maalouf, K. Sakhaee, J. Parks et al.

Ayşegül Kırca, M. Özkan, B. Cemeroǧlu

S. M. Alavi, J. Cosson