相关论文: Diffusion of muonium and hydrogen in diamond
Isolated hydrogen, deuterium, and muonium in diamond have been studied by path-integral molecular dynamics simulations in the canonical ensemble. Finite-temperature properties of these point defects were analyzed in the range from 100 to…
We present calculations of free energy barriers and diffusivities as functions of temperature for the diffusion of hydrogen in bcc-Fe. This is a fully quantum mechanical approach since the total energy landscape is computed using a new self…
Muonium (Mu), a bound state of a positively charged muon and an electron, can diffuse through crystal lattices and interact with defect centers in insulators and semiconductors. We demonstrate that this Mu's diffusive property can be used…
An understanding of hydrogen diffusion on metal surfaces is important, not just for its role in heterogeneous catalysis and hydrogen fuel cell technology, but also because it provides model systems where tunneling can be studied under…
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…
Hydrogen diffusion on metals exhibits rich quantum behavior, which is not yet fully understood. Using simulations, we show that many hydrogen diffusion barriers can be categorized into those with "parabolic-tops" and those with…
Hydrogen radical attacks and subsequent hydrogen migrations are considered to play an important role in the atomic-scale mechanisms of diamond chemical vapour deposition growth. We perform a comprehensive analysis of the reactions involving…
We have used diffusion quantum Monte Carlo (DMC) calculations to study the pressure-induced phase transition from the diamond to $\beta$-tin structure in silicon. The calculations employ the pseudopotential technique and systematically…
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…
Diamond is studied by path integral molecular dynamics simulations of the atomic nuclei in combination with a tight-binding Hamiltonian to describe its electronic structure and total energy. This approach allows us to quantify the influence…
In high spin molecules metal ions are coupled by ferro or antiferromagnetic short range interactions so that their magnetic moments are parallel or antiparallel to each other at temperatures (T) much smaller than the coupling constant J.…
A practical method for finding free energy barriers for transitions in high-dimensional classical and quantum systems is presented and used to calculate the dissociative sticking probability of H2 on a metal surface within transition state…
Quantum phase diffusion in a small underdamped Nb/AlO$_x$/Nb junction ($\sim$ 0.4 $\mu$m$^2$) is demonstrated in a wide temperature range of 25-140 mK where macroscopic quantum tunneling (MQT) is the dominant escape mechanism. We propose a…
Solid atomic hydrogen is one of the simplest systems to undergo a metal-insulator transition. Near the transition, the electronic degrees of freedom become strongly correlated and their description provides a difficult challenge for…
We investigate the pressure-induced metal-insulator transition from diamond to beta-tin in bulk Silicon, using quantum Monte Carlo (QMC) and density functional theory (DFT) approaches. We show that it is possible to efficiently describe…
The electronic and magnetic properties of neutral substitutional transition-metal dopants in dia- mond are calculated within density functional theory using the generalized gradient approximation to the exchange-correlation potential. Ti…
We study the rate of activated motion over multiple barriers, in particular the correlated double-jump of an adatom diffusing on a missing-row reconstructed Platinum (110) surface. We develop a Transition Path Theory, showing that the…
Nitrogen-vacancy center in diamond is a solid state defect qubit with favorable coherence time up to room temperature which could be harnessed in several quantum enhanced sensor and quantum communication applications, and has a potential in…
Diamond bulk irradiated with a free-electron laser pulse of 6100 eV photon energy, 5 fs duration, at the $\sim 19-25$ eV/atom absorbed doses, is studied theoretically on its way to warm dense matter state. Simulations with our hybrid code…
Polarized negative muons were used to study the behaviour of the boron acceptor centre in synthetic diamond produced by the chemical vapour deposition (CVD) method. The negative muon substitutes one of the electrons in a carbon atom, and…