A5033035540- Quantum, superfluid, helium dynamics
- Topological Materials and Phenomena
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Theoretical and Computational Physics
- Material Dynamics and Properties
- nanoparticles nucleation surface interactions
- stochastic dynamics and bifurcation
- Quantum and electron transport phenomena
- Advanced Thermodynamics and Statistical Mechanics
- Surface and Thin Film Phenomena
- Random lasers and scattering media
- Quantum optics and atomic interactions
- Advanced NMR Techniques and Applications
- High-pressure geophysics and materials
- Quantum many-body systems
- Cold Atom Physics and Bose-Einstein Condensates
- Nanopore and Nanochannel Transport Studies
- Aluminum Alloy Microstructure Properties
- Advanced ceramic materials synthesis
- Advanced Condensed Matter Physics
- Diamond and Carbon-based Materials Research
Rutgers, The State University of New Jersey
2019-2021
Cavendish Hospital
2018-2020
University of Cambridge
2016-2019
"Phonon Scattering in Condensed Matter." Optica Acta: International Journal of Optics, 28(1), p. 10
Abstract The microscopic motion of water is a central question, but gaining experimental information about the interfacial dynamics in fields such as catalysis, biophysics and nanotribology challenging due to its ultrafast motion, complex interplay inter-molecular molecule-surface interactions. Here we present an computational study nanoscale-nanosecond at surface topological insulator (TI), Bi $${}_{2}$$ <mml:math...
We derive an analytical expression for the intermediate scattering function of a particle on flat surface obeying Generalised Langevin equation, with exponential memory friction. Numerical simulations based extended phase space method confirm results. The simulated trajectories provide qualitative insight into effect that introducing finite timescale has line shapes. relative amplitude long-time tail shape is suppressed, but its decay rate unchanged, reflecting fact cutoff frequency kernel...
The jump distribution, a property of the motion adsorbates on corrugated surface, contains crucial information adsorbate-substrate energy dissipation processes. To provide means to study distributions in honeycomb array adsorption sites, we derive analytical expressions for intermediate scattering function (ISF) describing diffusion taking into account jumps up fourth-nearest neighbor length. enable testing against experimental or simulated data, develop global fitting routine that can be...
Nanoscopic clustering in a 2D disordered phase is observed for oxygen on Ru(0001) at low coverages and high temperatures. We study the coexistence of quasistatic clusters (with characteristic length $\ensuremath{\sim}9\text{ }\text{ }\AA{}$) highly mobile atomic which diffuses between energy-inequivalent, threefold hollow sites substrate. determine surprisingly activation energy diffusion $385\ifmmode\pm\else\textpm\fi{}20\text{ }\mathrm{meV}$. The minimum...
The use of helium diffraction patterns to study desorption processes is explored as a novel extension traditional methods based on specular reflection. sample, cyclooctatetraene, adsorbed Cu(111) provides rich but complex structure. modulation cyclooctatetraene by manifested convolution in the pattern, displaying an averaged super cell symmetry (73×73)R30°. adlayer expands during isothermal desorption, and change lattice constant direct measure coverage function time. We find energy 0.96 ±...
Exact expressions are derived for the intermediate scattering function (ISF) of a quantum particle diffusing in harmonic potential and linearly coupled to bath. The results valid arbitrary strength spectral density coupling. general, exact non-Markovian result is expressed terms classical velocity autocorrelation function, which represents an accumulated phase during event. imaginary part exponent ISF proportional phase, antisymmetric correlation time $t$. extend previous given Langevin...
A closed form of the disentangling theorem is used to derive an exact expression for quantum mechanical intermediate scattering function describing long-range coherent tunneling. The result applies a single particle in large periodic nearest-neighbor tight-binding system one spatial dimension, with localized site per unit cell. up assumption orthogonal states and substitution coordinate operator discrete representation diagonal on-site basis. expressed terms modified Bessel functions,...
The classical Langevin dynamics of a particle in periodic potential energy landscape are studied via the intermediate scattering function (ISF). By construction, performs coupled vibrational and activated jump motion with wide separation period mean residence time between jumps. long limit ISF is decaying tail proportional to that describes ideal absence vibrations. amplitude unity idealized models but reduced from by intra-well motion. Analytical estimates signature provided assuming...
We derive an analytical expression for the intermediate scattering function of a particle on flat surface obeying Generalised Langevin Equation, with exponential memory friction. Numerical simulations based extended phase space method confirm results. The simulated trajectories provide qualitative insight into effect that introducing finite timescale has line shapes. relative amplitude long-time tail shape is suppressed, but its decay rate unchanged, reflecting fact cutoff frequency kernel...