Topological Insulators in a Nutshell - Theory and Experiment

See how the mathematical field of topology turns out to play an important role in condensed matter physics.
Some references:
Topological order in a bismuth based compound: arxiv.org/abs/1409.3778
Symmetry classification scheme: arxiv.org/abs/0803.2786
Introduction to topology: www.amazon.com/Topology-2nd-J...
The role of topology in physics: www.amazon.com/Topology-Geome...
#Physics #VTuber #ENVtuber

[@eve_______]

Did I just find anime vtuber explaining math? Life is so fun and surprising.

[@m_obispo]

Never thought I'd live to watch a neko teach me condensed matter physics and topology... What a time to be alive. Well done, Xeno! I'd love to see more videos like this :)

[@MDNQ-ud1ty]

You didn't learn condensed matter physics nor topology... if you think you did then, well, you have some problems.

[@emirsekercilerzade9327]

@@MDNQ-ud1ty i think you have some problems. get a life

[@MDNQ-ud1ty]

@@emirsekercilerzade9327 So sorry. I didn't mean to burst your bubble and make you realize you are actually r3tarded and that your 93 IQ is not an A like you thought.

[@Gameknight2169]

Certainly the most absurd vtuber concept I've ever seen, but cool and helpful.

[@eleanorrepertoire1390]

Whew, as someone who is looking into starting research in topological insulators, this really helped as an intro/revision (I usually dabble more with GR stuffs)

[@XenosumPhysics]

yey glad it helped :3

[@zacharygu8757]

I never imagined that I would watch a vtuber teaching me condensed matter physics on youtube! You are my hero Xeno! As a Ph.D. working on photonic quantum technology, these materials are still some kind of relevant. Optical physicists tend to borrow concepts from other fields of physics, and topological photonics has also been extensively studied over the years. I have read a long review RMP 91, 015006, where the authors also explained topological states of matter. Anyway, thank you very much for your video, and I find it useful indeed~

[@jongwonroh4629]

OMG I AM ABSOLUTELY OBSESSED !!!! I sat with my jaw dropped for most of the video because you cleared up so many questions I had about this topic with such ease and elegance ! What a find ! I am so excited to see what projects you have in the future ! Also, what field of physics are you currently studying ? Thanks again for this, absolutely lovely !

[@jacobrose6661]

I never thought I'd be learning condensed matter physics from a VTuber but here I am! Thanks!!

[@omgwtfcake]

We will watch your career with great interest

[@forevermusicinmyheart8975]

This is so helpful! Please continue making more videos for future physics majors like me who sometimes (often) struggle in their classes.

[@Imaginary_darya]

I am so impressed that how great you explained the non-easy materials and provided the source as well!! Thank you for your effort! :)

[@chezz444]

That was amazing, I never thought I'd be learning condensed matter physics from a VTuber! Keep up the great work and cheers from another Physics + Vtuber fan! ｡◕‿◕｡

[@likestomeasurestuff3554]

That was incredibly helpful, thank you! Some well meant German advice, because you made my hair stand up a few times: "Schrödinger" is pronounced "Shrödinger" not "Skrodingger"; the ng is pronounced just like in the word "thing" and ö is between o and e

[@satyamjha_2]

Where were you? i was looking for you all along? never have I ever seen a youtube channel explain such advanced concepts with such great ease that I had to stop and subscribe first!

[@smiglani]

great video! You explain TI in an intuitive and interesting way. Looking forward to seeing more of this content.

[@GeoffryGifari]

the gapless edge state reminds me of phase transitions. Instead of phase change when temperature/pressure is varied, it changes when the material ends and the vacuum begins, with temperature and pressure fixed

[@diptiyadav007]

Thank you for simplifying such a complicated field.

[@wenjiegong5647]

This was actually so amazingly well explained

[@yamansanghavi]

I tried to read many papers and saw many lectures and I was still totally lost. Your video literally explained everything I wanted to know about Topological insulators. Thank you so so much.

[@AbhishekKumar-vc8yi]

Please don' t stop making videos, your explanations are great

[@robertmuller4225]

AMAZING! Keep it cooming bro

[@preetipokhriyal14]

Thanks for such clear explanation.

[@avant_excursion]

Excellent video. Thank you

[@jamesarnold791]

Very good video. One tiny correction, the Fermi level is not the energy level at which the highest energy electron exists (indeed there will be a distribution of electron energies and so the highest energy electron could technically and fleetingly exist at very high energy levels). The Fermi level is defined as the (theoretical) energy level that has a 50% change of being occupied at any given time, given the system is in thermodynamic equilibrium (kinda like a median).

[@NovaRuner]

A cute boy giving a super smart lecture on science stuff…. Yay!

[@mohammedqahosh1991]

Thanks for the awesome video; I hope to see more related to T.I. :)

[@designerguy_13anuragsharma59]

amazing Learning................thanks

[@aitorgarcia1147]

At first I thought this video was a joke, but as time went by, I was taking it more and more serious. Thanks Dr Katy!

[@DEEPAKKUMAR-mm9sj]

Nice 👍.. Please make more videos on topological insulators .. It will be very helpful for research students.I am working on a project on topological insulators.

[@emranshafaq1702]

very based resource for condensed matter physics tysm🎉

[@salviosama7942]

xenny we love you

[@dfcx1]

I have seen the future of education and it has cat ears.

[@erictheuser6677]

great stuff, pleas make viedeos about kagome metalls.

[@anarchistalhazen7084]

Superb

[@xinyanxiang4574]

Cool video!!!

[@afsanasharmin8177]

Hi Xeno, I like your explanation. You are a good teacher. Can you please also give a lecture on Non-Collinear AFM materials?

[@ashhenriquez918]

Can you please make more videos expanding on your explanation on band structures :3 ?

[@GeoffryGifari]

Makes me wonder, if we do have a topologically insulating material (like bismuth selenide) and form it into shapes with different topological invariance (ball, torus, shape with two holes, etc) will we see any different behavior? will the connection to topology be more apparent?

[@anime_freak373]

This is exactly who I need to teach me

[@tarifalmodares4679]

Great! Keep going!

[@Wo1fie]

Kyoot big brain anime boi ♥

[@user-tn7ks3ph4w]

I love this video!

[@dennywey9816]

Great explanation, systematic and kawaii!

[@physicslectures6155]

Is there any way I could like a video more than once?

[@raypenbar8305]

Awesome!

[@Ore00000]

Can you do a series on real analysis?

[@XylsTV]

shut the fuck up

[@GeoffryGifari]

so, for condensed matter systems, the "shape" analog is the hamiltonian (hamiltonians can be grouped into equivalence classes)? the "hole" is the band gap and the deformation is whatever continuous change of the band structure that preserve the band gap? should continuous deformation in this sense preserve the *width* of the band gap to be considered in one topological equivalence class?

[@XenosumPhysics]

nah, just like the size of the hole doesnt matter in topology, the width of the gap doesnt matter in topological insulator, at least theoretically realistically, though, you'd need to take into account other energy scales to compare. for example, experimentally, the band gap might be considered "zero" so long as its sufficiently smaller than the thermal energy of the environment

[@clydenathaniel8117]

Hey bro, what do u think about teaching a class or starting a journal club or a workshop in VRChat? Also, do u have a discord server?

[@Apoollo_11]

This guy deserve more subcribe

[@XenosumPhysics]

>:3 all the subs rawrr

[@bojo420]

Awesome video! But wouldn't this mean that all insulators have these edge states? So then all insulators are topological?

[@XenosumPhysics]

thanks! that's a good question- in order for an insulator to show edge states, its band topology needs to mismatch that of its environment (this is the condition that forces the gap to close and re-open at the boundary). since the vacuum/air have a trivial band topology (topological invariant of 0), insulators which also have a trivial band topology won't show edge states. so I think it's more appropriate to say that all insulators can be thought of as being topological (having *some* band topology, even if its 0), but that most of them are topologically trivial and don't show edge states, at least not in air.

[@Dk_Bwss]

If Fermi level is the highest occupied energy level then how can it be in the gap which is not supposed to have any electrons (forbidden state, not an eigenvalue of the hamiltonian)?

[@Lorch95]

We truly live in the best timeline

[@asussurge670]

thank you smart femboy v-tuber

[@XenosumPhysics]

u r welcome owo

[@JohnVKaravitis]

Have you located "the fourth hole"???

[@Grollm]

Just when I thought I couldn't love you more.

[@XenosumPhysics]

:3

[@gmanhero]

cute and smart, think i'm back in school trying to hit on my math tutor.

[@NovaRuner]

We so very much need more cute, smart, and knowledgeable Femboys to teach math and science. It would insulate us from ignorance. Draw them in with cuteness and fill the brain with science. 👍👍🤯

[@Hunter-zp9xb]

wow.... do you have a ph.d?

[@monadofcreation7262]

😮😇😎

[@SuperMaDBrothers]

I'm the 10,000th view. Also this video is actually really good LOOOOOOOOL. A lot of jargon but still.

[@wesleyrm]

6:38 shouldn't adiabatic transformations be very fast? To preserve quantum coherence (remain in the same eigenstate). en.wikipedia.org/wiki/Adiabatic_theorem Great video man! Goods references.

[@weldous]

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[@vzxvzvcxasd7109]

Oh my god, life is so fun

[@jeremydion6139]

I owe you a drink if your at APS this year

[@NoNTr1v1aL]

I think you meant to say disc instead of circle.

[@weldous]

ah.. imma cry... y did u say that at the end fak yoo

[@SomeGuy-ne3yl]

there is no way ... this is hilarious.

[@kdnguyen1444]

Fermi is pronounced like Fer-mee not Fer-my.

[@ARBB1]

What in the goddamn have I stumbled into

[@groli3335]

Dude wtf

[@Maximxls]

lol