Ashutosh Shukla

[Ashutosh Shukla @SciTalksAsh]

@ydnad0 @Pavan_KumarGV @IISERPune @SnehaBoby @chandrahul08 The collective scattering properties of the 3 particle and 4 particle assemblies are different which leads to this behaviour. We explore it in depth in the paper.

[G V Pavan Kumar @Pavan_KumarGV]

A new preprint from my lab @IISERPune :

We observe "Rotational Jamming of Optical Matter Driven by Chiral Light"

Super effort by: @SciTalksAsh @SnehaBoby @chandrahul08

The video shows optically bound gold nanoparticles getting jammed while rotating. The rotation is driven by polarization of light.

Abstract: Optical matter (OM), composed of optically bound metallic particles, can be rotated by transferring the spin angular momentum (SAM) of chiral light to the assembly. Rotating OM is a promising platform for optical micromachines, with potential applications in plasmofluidics and soft robotics. Understanding the dynamic states of such Brownian micro-mechanical systems is a relevant issue. One key problem is understanding kinetic jamming and clogging. Studies of driven multiparticle systems have revealed that under suboptimal driving, the systems can stop moving, showing jamming transitions. It is important to identify dynamic regimes where crowding competes with driving and is susceptible to jamming in the context of optical micromachines. Through experiments supported by numerical simulations, we reveal assemblies with well-defined hexagonal or triangular symmetry that efficiently harness the SAM of incident chiral light, resulting in stable rotation. However, as the plasmonic-particle assembly grows and its dimensions approach the beam waist, new particles can disrupt this order. This causes a transition to a fluid-like state with less-defined symmetry, correlated with a significant reduction in transferred torque, causing rotation to stagnate or cease. We suggest this behaviour is analogous to a rotational jamming transition, where the rotational motion is arrested. Our findings establish a clear relationship between the structural symmetry of the OM assembly and its ability to harness SAM, providing new insights into controlling chiral light-matter interactions and offering a novel platform for studying jamming transitions.

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As usual, we welcome comments and criticism

Link to the arXiv preprint in reply

[G V Pavan Kumar @Pavan_KumarGV]

To wind up the year, we have a manuscript acceptance in ACS Photonics.. kudos to @chandrahul08 and @SciTalksAsh...super effort by them & thanks to the anonymous reviewers who made us think...

[G V Pavan Kumar @Pavan_KumarGV]

At @compflu2024,
@SnehaBoby
from our group got best poster award

She presented our recent work on optical binding of gold nanoparticles..

Congratulations Sneha!

[G V Pavan Kumar @Pavan_KumarGV]

link to arxiv preprint : https://t.co/3AOIbIwKO5

[G V Pavan Kumar @Pavan_KumarGV]

We have a new preprint - Synchronized motion of gold nanoparticles in an optothermal trap

The central circle indicates anchored gold nanoparticles stuck to the glass, & the 2 moving circles are gold colloids that are trapped synchronously due to the optothermal potential.

1/2

[G V Pavan Kumar @Pavan_KumarGV]

We have an arxiv preprint :

We explore some dynamic regimes of optical matter driven by heat+light...

https://t.co/noTjSSj94w

@chandrahul08 @SciTalksAsh & Sneha Boby

[IISER Pune Optics League @iiserpoptica]

IISER Pune Optics Team participated in the National Science Day event at IISER Pune. We showed the concepts of optics & our research to school students and teachers using simple experiments!

We thank @ScienceActivity and @IISERPune for the amazing opportunity! @OpticaWorldwide

[IISER Pune Optics League @iiserpoptica]

We will be hosting our alumni, Deepak Kumar Sharma, at @IISERPune for an offline talk on 'All-dielectric metasurfaces for 3D detection and holographic projection.' March 1st, 4PM in the Seminar Room 31 in the Main Building.
@IiserPphysics @OpticaWorldwide

[IISER Pune Optics League @iiserpoptica]

We are happy to announce an amazing event this week! Prof Deepak Jain will talk about The Art of Self-Promotion for Young Researchers! The event is in person on Feb 15th, 11AM, in Seminar room 31 in Main Building @IISERPune
Drop in if you're around
@OpticaWorldwide

[IISER Pune Optics League @iiserpoptica]

We are happy to have another interesting online talk in our seminar series! @SileNicChormaic will give a talk titled: 'From cold atoms to microbeads - manipulation using ultrathin optical fibres'
Feb 13, 12PM IST on Zoom @ https://t.co/ThFGtHjfll
@IISERPune @OpticaWorldwide

[Kanishka Rajoria @KanishkaRajori7]

Thanks to @ISPPhotobiology for giving me this opportunity to present my work.

[IISER Pune Optics League @iiserpoptica]

Drop by today in LHC101 at 5:30 for an insightful event. Event open to all! @IISERPune

[IISER Pune Optics League @iiserpoptica]

Announcing a movie screening at @IISERPune with @grumpeoldman. FireInTheBlood shows the struggle of poor countries against bigPharma and their patent laws to have access to life saving generic drugs. Screening will be followed by QnA on law, innovation, and IPR. @OpticaWorldwide

[ACS Photonics @ACSPhotonics]

Researchers in @Pavan_KumarGV @IISERPune experimentally probe emergence of directional rotation in active-passive colloidal system. It is at the interface of optical trapping, active-matter and thermodynamics
@chandrahul08 @ChaudharyEksha @pauldiptabrata

https://t.co/nTeCzD2BVH

[IISER Pune Optics League @iiserpoptica]

Had a fun interaction session yesterday with class 11th students from Pune.
Did Optics demonstrations explaining interference, polarisation, and light-liquid crystals interactions.
@OpticaWorldwide StudentChapter
Advisor: @Pavan_KumarGV, @IISERPune
PhotoCredits:@ChaudharyEksha

[IISER Pune Optics League @iiserpoptica]

Had 'enlightening' #outreach session with students of @UnivOfPune. #Optics demonstrations explaining interference, polarisation, and interactions of light with liquid crystals.
@OpticaWorldwide Student Chapter
Advisor: @Pavan_KumarGV, @IISERPune

[G V Pavan Kumar @Pavan_KumarGV]

📹New video blog : I tell the story of Dan Shechtman and make some predictions (mainly physics) for Nobel this year...

https://t.co/Ph1J1Htaz6

[IISER Pune Optics League @iiserpoptica]

We've uploaded the recent online seminar on Active matter by @Giorgio_Volpe on our Chapter's YouTube channel.
Find it here. https://t.co/rQ9I0ZtUwf

We also have many other talks uploaded there. Go check them out.
@IISERPune @Pavan_KumarGV @IiserPphysics

[Prof. Eliot Jacobson @EliotJacobson]

Our f&%kery knows no upper limits.

That's right, global surface temperatures just set a new record anomaly yesterday, a full 0.84°C above the 1991-2020 mean, beating the previous high of 0.82°C set earlier this year and the previous record anomaly of 0.83°C set in 2016.