Related papers: Atom-Tunneling in Chemistry
We consider theoretically ionization of an atom by neutrino impact taking into account electromagnetic interactions predicted for massive neutrinos by theories beyond the Standard Model. The effects of atomic recoil in this process are…
Recent experimental data on the diffusion coefficient of carbon in alpha-iron below liquid nitrogen temperature (LNT) question the classical approach to the observed temperature dependence. As the temperature is lowered below LNT, the…
Controlling interactions between cold molecules using external fields can elucidate the role of quantum mechanics in molecular collisions. We create a new experimental platform in which ultracold rubidium atoms and cold ammonia molecules…
We consider tunneling of two interacting atoms with an even spatial symmetry. The atoms are prepared in two lowest excited states with respect to relative and center-of-mass motions. We observe monotonic and non-monotonic dependence of the…
We study the quantum tunnel effect through a potential barrier employing a semiclassical formulation of quantum mechanics based on expectation values of configuration variables and quantum dispersions as dynamical variables. The evolution…
A formula suitable for a quantitative evaluation of the tunneling effect in a ferromagnetic particle is derived with the help of the instanton method. The tunneling between n-th degenerate states of neighboring wells is dominated by a…
A theoretical and numerical investigations of the quantum tunneling of the domain walls in ferromagnets and weak ferromagnets was performed taking into account the interaction between walls and thermal excitations of a crystal. The…
Classical phase transitions, like solid-liquid-gas or order-disorder spin magnetic phases, are all driven by thermal energy fluctuations by varying the temperature. On the other hand, quantum phase transitions happen at absolute zero…
Quantum mechanical methods have been devised for the elucidation and clarification of reaction paths of chemical processes over decades. While they are typically deployed in routine calculations on systems for which some insights have…
We study the system that two atoms simultaneously interact with a single-mode thermal field via different couplings and different spontaneous emission rates when two-photon process is involved. It is found that we indeed can employ the…
We apply quantum rate theory to calculate the transition rates as hydrogen or deuterium atoms escape from a vacancy trap in iron into a neighbouring metastable site. We determine transition rates and corresponding activation energies over a…
Quantum proton tunneling (QPT) in the two representative multi-electron/-proton transfer electrode processes, i.e. hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR), was investigated by using polycrystalline platinum…
The influence of quantum fluctuations on electron transport through small metallic islands with Coulomb blockade effects is studied beyond the perturbative regime. In tunnel junctions with low resistance higher order coherent processes and…
Coulomb blockade phenomena and quantum fluctuations are studied in mesoscopic metallic tunnel junctions with high charging energies. If the resistance of the barriers is large compared to the quantum resistance, transport can be described…
The adsorption and diffusion of hydrogen atoms on Cu(001) are studied using first-principles calculations. By taking into account the contribution of zero-point energy (ZPE), the originally identical barriers are shown to be different for H…
Electronic transport in diatomic molecules (two-level systems) connected to metallic contacts is analyzed in the presence of competing electron-electron and electron-phonon interactions. We show that phonon emission and absorption processes…
Molecular hydrogen (H$_2$) plays a critical role in astrophysical processes from galaxy evolution to the formation of planets. While the dominant formation channel in the interstellar medium is considered as dust-catalyzed H$_2$ formation,…
The racemization of amino acids constitutes one of the most elemental and critical reactions, holding primitive significance for understanding the life's origin and maintenance. Nevertheless, its mechanism at the atomic level has been…
Quantum annealing is analogous to simulated annealing with a tunneling mechanism substituting for thermal activation. Its performance has been tested in numerical simulation with mixed conclusions. There is a class of optimization problems…
Quantum effects in condensed matter normally only occur at low temperatures. Here we show a large quantum effect in high-pressure liquid hydrogen at thousands of Kelvins. We show that the metallization transition in hydrogen is subject to a…