# s-gst: controlling light-harvesting in molecular ensembles

AA << propose that the trap is a Frenkel exciton state formed much below the main exciton band edge due to an environmentally induced heavy-tailed Lévy disorder. This points to disorder engineering as a new avenue in controlling light-harvesting in molecular ensembles >>

Merdasa A, Jiménez Á, et al. Single
Lévy states-disorder induced energy funnels in molecular aggregates. Nano Lett. 2014 Dec 10;14(12):6774-81. doi: 10.1021/nl5021188. Epub 2014 Nov 7. PubMed PMID:
25349900.

http://pubs.acs.org/doi/abs/10.1021/nl5021188

also

"Frenkel exciton state" in:

https://journals.aps.org/search/

https://arxiv.org/find/all/1/all:+AND+state+AND+Frenkel+exciton/0/1/0/all/0/1

# evol: spontaneous, immediate asymmetry, the chiral twist

<< When holding a right hand in front of a mirror, one can see a reflected image of a left hand and vice versa. In 1848, Louis Pasteur discovered that organic molecules are much like our hands: they come in mirror-image pairs of left- and right-handed variants. Nowadays, we know that this handedness or chirality (from the Greek word for "hand") is a hallmark of organic molecules. >>

<< Organic molecules are rich in carbon atoms, which form bonds to create either a right or a left "nano-hand." Yet, puzzlingly, life almost always selects to exclusively use one of the two mirror-image twins—a phenomenon called homochirality. For example, terrestrial life is based on left-handed amino acids and right-handed sugars. >>️️

<< A model now proposes a novel explanation for the emergence of homochirality in life—a longstanding puzzle about the origin of life on Earth. >>️

<< Homochirality emerges spontaneously in prebiotic chemical networks that adapt to optimize energy harvesting from the environment. Previously, it was believed that chiral symmetry breaking requires multiple loops of auto-catalysis, which increasingly produces one enantiomer of a molecule while inhibiting the formation of the other. However, the IBS team's results showed that the underlying mechanism of symmetry breaking is very general, as it can occur in large reaction systems with many random molecules and does not require sophisticated network architectures. It was found that this sharp transition to homochirality stems from the self-configuration of the reaction network in order to achieve more efficient harvesting of energy from the environment. >>️

Learning chemical networks give life a chiral twist. Institute for Basic Science. Apr 26, 2022. 

https://phys.org/news/2022-04-chemical-networks-life-chiral.html

William D. Pineros, Tsvi Tlusty. Spontaneous chiral symmetry breaking in a random driven chemical system. Nat Commun 13, 2244. doi: 10.1038/ s41467-022-29952-8. Apr 26, 2022.

https://www.nature.com/articles/s41467-022-29952-8

Also

keyword 'chiral' in FonT

https://flashontrack.blogspot.com/search?q=chiral

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

Keywords: evolution, gst, randomness, self-assembly, self-configuration, break symmetry, asymmetry, chiral, chirality  

# phys: synchronizing nano 'Pendulums'

AA << report synchronization of the mechanical dynamics of a pair of optomechanical crystal cavities that, (..) are intercoupled with a mechanical link and support independent optical modes. In this regime they oscillate in antiphase, >>

AA << also show how to temporarily disable synchronization of the coupled system >>

Colombano MF, Arregui G, et al. Synchronization of Optomechanical Nanobeams by Mechanical Interaction. Phys. Rev. Lett. 123, 017402. July 1, 2019.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.017402  

Katherine Wright. Synopsis: Synchronizing Nanosized "Pendulums". Jul 1, 2019.

https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.123.017402 

# gst: expanding 'bubbles' of distortion in the nano lattice of a material, a glimpse of polarons

 << Polarons are fleeting distortions in a material's atomic lattice that form around a moving electron in a few trillionths of a second, then quickly disappear. As ephemeral as they are, they affect a material's behavior, >> 

 << When you put a charge into a material by hitting it with light, like what happens in a solar cell, electrons are liberated, and those free electrons start to move around the material, (..) Soon they are surrounded and engulfed by a sort of bubble of local distortion—the polaron—that travels along with them, (..)  Some people have argued that this 'bubble' protects electrons from scattering off defects in the material, and helps explain why they travel so efficiently to the solar cell's contact to flow out as electricity. >> Burak Guzelturk.

<< The hybrid perovskite lattice structure is flexible and soft—like a strange combination of a solid and a liquid at the same time, (..) and this is what allows polarons to form and grow. >> Aaron Lindenberg.

Glennda Chui. First glimpse of polarons forming in a promising next-gen energy material. SLAC National Accelerator Laboratory. Jan 04, 2021.

https://phys.org/news/2021-01-glimpse-polarons-next-gen-energy-material.html

Burak Guzelturk, Thomas Winkler, et al.  Visualization of dynamic polaronic strain fields in hybrid lead halide perovskites. Nat. Mater. doi: 10.1038/ s41563-020-00865-5. 04 Jan 4, 2021.

https://www.nature.com/articles/s41563-020-00865-5   

# gst: nano entities that are both twisted and untwisted at the same time

<< Scientists who study the nanoscale-with molecules and materials 10,000 smaller than a pinhead-need to be able to test the way that some molecules twist, known as their chirality, because mirror image molecules with the same structure can have very different properties. >>

<< Recently, a new class of nanoscale materials have been developed to help distinguish the chirality of molecules. These so-called 'nanomaterials' usually consist of tiny twisted metal wires, that are chiral themselves. However, it has become very hard to distinguish the twist of the nanomaterials from the twist of the molecules they are supposed to help study. >>

To solve this problem AA << created a nanomaterial that is both twisted and it is not. This nanomaterial has equal number of opposite twists—meaning they cancel each other out.  >>

<< Using a mathematical analysis of the material's symmetry properties, the team discovered a few special cases, which can bring the 'hidden' twist to light and allow very sensitive detection of chirality in molecules. >>

Chris Melvin. Scientists create a nanomaterial that is both twisted and untwisted at the same time. University of Bath. Sep 13, 2019   https://m.phys.org/news/2019-09-scientists-nanomaterial-untwisted.html  

Christian Kuppe,  Xuezhi Zheng, et al. Measuring optical activity in the far-field from a racemic nanomaterial: diffraction spectroscopy from plasmonic nanogratings. Nanoscale Horizons.  Issue 5, 2019.  doi: 10.1039/C9NH00067D.   https://pubs.rsc.org/en/content/articlelanding/2019/NH/C9NH00067D

# gst: the strong impact on nanosheets by the weak van der Waals force

<< Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls. >> 

<< Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky, (..) When you put a large, flat particle on a large, flat surface, there's a lot of contact, and it's enough to permanently deform a particle that's really thin and flexible. >> 

Matt Jones. 

<< the ubiquitous, "weak" van der Waals force was sufficient to indent a rigid silver nanosheet. The phenomenon suggests possible applications in nanoscale optics or catalytic systems. >>

<< In further experiments, (..) nanospheres could be used to control the shape of the deformation, from single ridges when two spheres are close, to saddle shapes or isolated bumps when the spheres are farther apart. >> 

Mike Williams. Weak force has strong impact on nanosheets. Rice University. Dec 15, 2020. 

https://phys.org/news/2020-12-weak-strong-impact-nanosheets.html

Sarah M. Rehn, Theodor M. Gerrard-Anderson, et al. Mechanical Reshaping of Inorganic Nanostructures with Weak Nanoscale Forces. Nano Lett. doi: 10.1021/ acs.nanolett.0c03383. Dec 10, 2020. 

https://pubs.acs.org/doi/10.1021/acs.nanolett.0c03383  

Also

keyword 'van der Waals' in FonT

https://flashontrack.blogspot.com/search?q=van+der+Waals

# gst: apropos of nano vortices: the stabilization of skyrmions by weak higher-order exchange interactions

<< Tiny magnetic whirls that can occur in materials—so-called skyrmions— hold high promises for novel electronic devices or magnetic memory in which they are used as bits to store information. A fundamental prerequisite for any application is the stability of these magnetic whirls. >>

<< Previously, a standard model of the relevant magnetic interactions contributing to the (energy) barrier has been established. >>

<< one type of magnetic interactions has so far been overlooked. In the 1920s Werner Heisenberg could explain the occurrence of ferromagnetism by the quantum mechanical exchange interaction which results from the spin dependent "hopping" of electrons between two atoms. "If one considers the electron hopping between more atoms, higher-order exchange interactions occur," says Dr. Souvik Paul, (..). However, these interactions are much weaker than the pair-wise exchange proposed by Heisenberg and were thus neglected in the research on skyrmions. >>

<< Based on atomistic simulations and quantum mechanical calculations (..)  (AA) have now explained that these weak interactions (at a higher temperature than room temperature) can still provide a surprisingly large contribution to skyrmion stability. Especially the cyclic hopping over four atomic sites (..) influences the energy of the transition state extraordinarily strongly (..), where only a few atomic bar magnets are tilted against each other. Even stable antiskyrmions were found in the simulations which are advantageous for some future data storage concepts but typically decay too fast. >>

Julia Siek­mann. Scientists find a new mechanism for the stabilization of skyrmions. Kiel University. Sep 21, 2020.

https://phys.org/news/2020-09-scientists-mechanism-stabilization-skyrmions.html

Paul, S., Haldar, S., von Malottki, S. et al. Role of higher- order exchange interactions for skyrmion stability. Nat Commun 11, 4756. doi: 10.1038/ s41467-020-18473-x. Sep 21, 2020.

https://www.nature.com/articles/s41467-020-18473-x   

# s-nano: self-assembly, also in nanotech

<< some nanomaterials can be coaxed into snapping themselves into desired formations-a process called self-assembly >>

AA << have just developed a way to direct the self-assembly of multiple molecular patterns within a single material, producing new nanoscale architectures.  >>

Smarter  self-assembly  opens  new  pathways  for  nanotechnology. August  8,  2016.

http://m.phys.org/news/2016-08-smarter-self-assembly-pathways-nanotechnology.html

A. Stein, G. Wright, et al. Selective directed self-assembly of coexisting morphologies using block copolymer blends. Nature Communications 7, Article number: 12366 (2016) doi:10.1038/ncomms12366

http://www.nature.com/articles/ncomms12366

# bot-nano: programmable molecular machines to assemble molecular machines

<< It has been convincingly argued that molecular machines that manipulate individual atoms, or highly reactive clusters of atoms, with Angstrom precision are unlikely to be realized >>

AA << detail an artificial molecular machine that moves a substrate between different activating sites to achieve different product outcomes from chemical synthesis >>

AA << anticipate that future generations of programmable molecular machines may have significant roles in chemical synthesis and molecular manufacturing >>

Salma Kassem, Alan T. L. Lee, et al.  Stereodivergent synthesis with a programmable molecular machine. Nature 2017; 549: 374–378. Sep 21. doi: 10.1038/nature23677

http://www.nature.com/nature/journal/v549/n7672/full/nature23677.html

Scientists create world’s first ‘molecular robot’ capable of building molecules. Sep 20, 2017

http://www.manchester.ac.uk/discover/news/scientists-create-worlds-first-molecular-robot-capable-of-building-molecules/

CAMERA - Chemistry at Manchester Explains Research Advances

https://m.youtube.com/channel/UCXf3CFkyGpa2eIeT5wz_Prw/featured

# gst: like steering a marble through a tilting labyrinth, randomness seems to quickly deliver specific outcomes.

<< According to the infinite monkey theorem, a monkey randomly hitting the keys of a typewriter will eventually write something worth reading—but it might take a few trillion years of trying. For those lacking the patience to wait, (AA)  now show that randomness can deliver specific outcomes much more quickly.  Simulating a 2D nanocluster of a dozen particles, (they) determine the temperature at which thermal fluctuations can most quickly rearrange those particles into a predetermined shape. They find that this time can be dramatically cut by applying an appropriate macroscopic force to the particles. >>

<< The duo also simulated nanoclusters that were subject to a macroscopic force field, for example, metallic nanoparticles in an electric field. Like steering a marble through a tilting labyrinth, they found the optimal global force to apply at each iteration such that the nanocluster navigated the space of possible configurations several orders of magnitude more quickly. >>️️

Marric Stephens. Rearranging Nanoclusters Using Randomness. Physics 15, s83. Jun 22, 2022. 

https://physics.aps.org/articles/v15/s83

Francesco Boccardo, Olivier Pierre-Louis. Controlling the Shape of Small Clusters with and without Macroscopic Fields. Phys. Rev. Lett. 128, 256102. Jun 22, 2022.  

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.256102

Also

keyword 'random' in FonT:

https://flashontrack.blogspot.com/search?q=random

keyword 'error' | 'fuzzy' | 'noise'  in FonT 

https://flashontrack.blogspot.com/search?q=error

https://flashontrack.blogspot.com/search?q=fuzzy

https://flashontrack.blogspot.com/search?q=noise

keywords 'errore' | 'errori' in Notes (quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=errore

https://inkpi.blogspot.com/search?q=errori

keywords 'jelly roll' in FonT

https://flashontrack.blogspot.com/search?q=jelly+roll

Keywords: gst, nano, nanocluster, fluctuations, randomness, noise

# rmx-s-chem: a bizarre material

<< lanthanum aluminate film on a strontinum titanate crystal >> ... plus water

<< (..) a mysterious material emits ultraviolet light and has insulating, electrical conducting, semiconducting, superconducting, and ferromagnetic properties — all controlled by surface water >>

http://www.kurzweilai.net/mystery-material-stuns-scientists

Mohammad A. Islam, Diomedes Saldana-Greco,  et al.  Surface Chemically Switchable Ultraviolet Luminescence from Interfacial Two-Dimensional Electron Gas. Nano Letters, 2015; DOI: 10.1021/acs.nanolett.5b04461

http://pubs.acs.org/doi/10.1021/acs.nanolett.5b04461

# tech: coloured walls and cities by nano pixels (also for immediate hack poetry)

<< Plasmonic metasurfaces are a promising route for flat panel display applications due to their full color gamut and high spatial resolution. >>

AA << present scalable electrically driven color-changing metasurfaces constructed using a bottom-up solution process that controls the crucial plasmonic gaps and fills them with an active medium. >>

<< ... which are a hundredfold thinner than current displays. >>

Jialong Peng, Hyeon-Ho Jeong, et al. Scalable electrochromic nanopixels using plasmonics. Science Advances   Vol. 5, no. 5, eaaw2205  doi: 10.1126/sciadv.aaw2205. May 10, 2019.

https://advances.sciencemag.org/content/5/5/eaaw2205

Smallest pixels ever created could light up color-changing buildings. University of Cambridge. May 10, 2019.

https://m.phys.org/news/2019-05-smallest-pixels-color-changing.html

FonT

2107 - coll' anse d' apostrofo. Jan 14, 2007

<< traccia coll' anse d' apostrofo un virtuosistico //
irriproducibile tagete // >>

https://inkpi.blogspot.com/2007/01/2107-coll-anse-d-apostrofo.html

# gst: apropos of hybrid nanostructures, the Kondo cloud effects on 'impurities' (inside superconductors).

<< when a metal contains magnetic impurities, conduction electrons can form a screening cloud, which essentially screens the impurity's spin. This physical phenomenon is known as the Kondo effect; thus, the resulting cloud is referred to as a Kondo cloud. >>

<< While the behavior of the Kondo cloud in normal systems is well-understood, its properties in the presence of superconducting materials have not yet been explored in depth. So far, most physicists have believed that the screening of impurity spins in hybrid nanostructures takes place predominantly in the screened, rather than in the unscreened, quantum phase. >>

<< The system we considered exhibits a quantum phase transition when the ground state changes between the Kondo state and the so-called Shiba state, (..) Up to now, it was believed that the screening occurs in the Kondo phase. Quite strikingly, we have however, demonstrated that the Kondo cloud exists also in the unscreened phase. >>  Ireneusz Weymann.

Ingrid Fadelli. Study predicts the behavior of a Kondo cloud in a superconductor. Phys.org. Nov  23, 2021. 

https://phys.org/news/2021-11-behavior-kondo-cloud-superconductor.html

Catalin Pascu Moca, Ireneusz Weymann, et al. Kondo Cloud in a Superconductor.  Phys. Rev. Lett. 127, 186804. Oct 27, 2021.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.186804

keywords: gst, nano, hybrid nanostructure, superconductor, transition, impurity, Kondo cloud, Kondo effect

# gst: weird matter, the 'ballistic resonance' paradox; amplitude of mechanical vibrations can grow without external influence

AA << discovered a new physical phenomenon of 'ballistic resonance', where mechanical oscillations can be excited only due to internal thermal resources of the system. >>

<< The discovered phenomenon describes that the process of heat equilibration leads to mechanical vibrations with an amplitude that grows with time. The effect is called ballistic resonance. >>

<< Over the past few years, our scientific group has been looking into the mechanisms of heat propagation at the micro and nano levels. We found out that at these levels, heat doesn't spread in the way we expected it to: for example, heat can flow from cold to hot. This behavior of nanosystems leads to new physical effects, such as ballistic resonance, >> Vitaly Kuzkin.

Scientists have discovered a new physical paradox. Peter the Great Saint-Petersburg Polytechnic University. Jul 13, 2020.

https://phys.org/news/2020-07-scientists-physical-paradox.html

<< coupling between macroscopic dynamics and quasiballistic heat transport gives rise to mechanical vibrations with growing amplitude. This phenomenon is referred to as ballistic resonance. At large times, these mechanical vibrations decay monotonically >>

Vitaly A. Kuzkin, Anton M. Krivtsov. 

Ballistic resonance and thermalization in the Fermi-Pasta-Ulam-Tsingou chain at finite temperature. Phys. Rev. E 101, 042209. Apr 16, 2020.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.101.042209