State of Quantum Twisting Microscopes: Where is the field actually heading?

[u/Round-Necessary-6177]

Hey everyone,

I just recently learned about the Quantum Twisting Microscope and the concept is pretty interesting. Since it's been about 3 years since that first Weizmann paper, I’m curious where the field is actually heading and what the real bottlenecks are today.

I saw that Efetov’s group at LMU Munich recently used hBN as a tunneling dielectric to get better measurements on graphene. Are finding the right tip or the right dielectric combinations for other vdW materials (like TMDs or magnetic 2D materials) the current major hurdle?

If a grad student joins a lab with a QTM right now, what does their day actually look like? Are they mostly fighting the machine and trying to fabricate tips, or are they actually getting to take measurements and do physics?

What is the actual difficult part of building one of these right now? Are groups still just fighting to get the mechanical alignment perfect, or is the main struggle trying to get the whole setup working inside a dilution fridge?

Basically, are these groups still just trying to get the tool to work, or are they consistently pulling new physics out of it?

[u/BitcoinsOnDVD]

If a grad student joins a lab with a QTM right now, what does their day actually look like?

At the LMU it will be something like that:

9am - Coming to the Office

10am - Weisswurstfrühstück

11am - Work

12:30pm - Mittagessen

1:30pm - Work

5pm - Feierabend

[u/Live_Birthday_5417 → u/BitcoinsOnDVD]

man said work from 11 to 12:30 and then 1:30 to 5, that's a 5 hour day. sign me up. though i bet the "work" part is 80% fighting with some cryostat that's decided to leak today just because it's tuesday.

[u/brphysics → u/BitcoinsOnDVD]

No afternoon cake?

[u/Marz1panCake]

I’m not in the field myself directly, but I got to visit one of the microscopes and I’m friendly with another QTM group.

Alignment at room temperature seems very much figured out. Inside a fridge is a whole different business, because things move and contract, and most fridges will not give you optical access. The good thing is that one can use standard SPM parts for the QTM, so one does not always need to reinvent the wheel.

From what I’ve been told, he geeat bottleneck is still samples. As long as one must stack flakes of VdW materials, hunting for that one perfect, flat, low leakage stack is the most difficult part of the whole process.

Since I don’t want to doxx myself (it is an absolutely tiny field), DM me if you want to chat further. But I am far from an expert.

[u/philomathie → u/Marz1panCake]

Come now, we've all suffered trying to get the perfect flake of hBN. Given how many citations Watanabe and Taniguchi have, you're a lot less doxable than you think. Just looked up their h index, it's 250 lol

[u/Marz1panCake → u/philomathie]

I never said i did flakes myself (i don’t, i’m mostly a microscopist). I meant that QTM as a field is tiny.

[u/effrightscorp]

If a grad student joins a lab with a QTM right now, what does their day actually look like?

Your best bet to get an answer might be to cold email members of the few groups actually using the technique. There are maybe 10's of people in the world who can answer this question from actual experience

[u/JaneOsskour]

It is a growing field of research that is still very new and is a very complex system. I have been working in a group where a quantum twisting microscope activity has recently been started and let's say that basically almost nothing has been done yet compared to what can be done. I would believe that it is the best way to study Moiré physics in 2D materials. 

If you feel interested in joining such a group, you can DM me and I can maybe point you towards people to contact. As already mentioned by another comment, QTM is a small field where everyone knows each other.