41 research outputs found
Noise bridges dynamical correlation and topology in coupled oscillator networks
We study the relationship between dynamical properties and interaction
patterns in complex oscillator networks in the presence of noise. A striking
finding is that noise leads to a general, one-to-one correspondence between the
dynamical correlation and the connections among oscillators for a variety of
node dynamics and network structures. The universal finding enables an accurate
prediction of the full network topology based solely on measuring the dynamical
correlation. The power of the method for network inference is demonstrated by
the high success rate in identifying links for distinct dynamics on both model
and real-life networks. The method can have potential applications in various
fields due to its generality, high accuracy and efficiency.Comment: 2 figures, 2 tables. Accepted by Physical Review Letter
Magic angle in thermal conductivity of twisted bilayer graphene
We report a local minimum in thermal conductivity in twisted bilayer graphene
(TBG) at the angle of 1.08, which corresponds to the 'magic angle' in
the transition of several other reported properties. Within the supercell of a
moir\'e lattice, different stacking modes generate phonon scattering sites
which reduce the thermal conductivity of TBG. The thermal magic angle arises
from the competition between the delocalization of atomic vibrational
amplitudes and stresses on one hand, and the increased AA stacking density on
the other hand. The former effect weakens the scattering strength of a single
scatterer while the latter one increases the density of scatterers. The
combination of these two effects eventually leads to the apparition of the
highlighted irregularity in heat conduction. The manifestation of a magic
angle, disclosing new thermal mechanisms at nanoscale, further uncovers the
unique physics of two-dimensional materials.Comment: 15 pages, 5 figure
Controlling complex networks: How much energy is needed?
The outstanding problem of controlling complex networks is relevant to many
areas of science and engineering, and has the potential to generate
technological breakthroughs as well. We address the physically important issue
of the energy required for achieving control by deriving and validating scaling
laws for the lower and upper energy bounds. These bounds represent a reasonable
estimate of the energy cost associated with control, and provide a step forward
from the current research on controllability toward ultimate control of complex
networked dynamical systems.Comment: 4 pages paper + 5 pages supplement. accepted for publication in
Physical Review Letters;
http://link.aps.org/doi/10.1103/PhysRevLett.108.21870