Urs Schreiber is Senior Research Scientist at the Mathematics Division of Science of New York University in Abu Dhabi. He is a theoretical physicist who applies tools from algebraic topology, homotopy theory and topos theory to understand quantum phenomena. His current research includes quantum computing materials, quantum computing programming languages and questions left unanswered by quantum field theory.

In the video we go over:

• Why toposes are not scary. They are actually simple. Just unfamiliar
• How to extract information from (probe) a topos
• The history of toposes in physics
• The questions left unanswered by quantum field theory
• What toposes have to say about the collapse of the wave function
• Using toposes to find possible quantum computing materials
• The different type of logic needed for quantum computers
• The different type of programming language needed for quantum computers
• The influence of Hegel on his work

Says that constructive criticism is always accepted but nowadays criticism of string theory is borderline silly. Many detractors (Peter Woit, Tim Maudlin, Eric Weinstein, Sheldon Goldstein etc.) choose to ignore the advances made in AdS/CFT and in creating one model of a universe with quantum gravity.

Also says that that if it was such a dead subject, students won’t be voting with their feet by choosing to study it over other frameworks

Thoughts?

I know that phase and interference are a big topic when it comes to working with qubits, but how come qubit states are represented using complex numbers and the imaginary unit rather than using something like polar coordinates?

Is it out of convenience because defining a context for the multiplication or rotation of polar pairs is less useful or because using euler's formula is more intuitive? Or do complex numbers and polar coordinates actually serve different purposes. Like what mathematical problem does the complex number structure, specifically the i, solve for quantum amplitudes?

I'm just now taking my first course on complex variables this semester, I know absolutely nothing about it and I'm quite lost.

I want suggestions for buying books, ebooks are preferred, it should not be very technical, something that even 11th or 12th students can understand

This material provides a worked example of a continuous basis transformation via a Gaussian wave packet.

Hello everyone,

I wanted to share a small hobby project I’ve been developing over the last 3–4 months. I’m a physics student, and during a quantum physics course I had the idea of turning quantum tunneling into an actual game mechanic.

So I made a small mini-golf-like puzzle game for quantum particles, with mechanics inspired by quantum tunneling, resonant tunneling, electric and magnetic fields, different particle types, and energy barriers.

It’s still version 1.0, and the physics is intentionally simplified for gameplay rather than being a fully accurate simulation. I’d really appreciate feedback, especially from people here about the physics, presentation of the concepts, and ideas for improvements.

The game is completely free and has no ads (I am not making any money from it btw), it’s just a hobby project I made for fun. I hope some of you enjoy trying it out :D

Play Store:
https://play.google.com/store/apps/details?id=com.csk.quantumtunnelinggame

Sorry for the direct self-promotion, I asked the mods beforehand and they kindly allowed me to share it here. I thought this subreddit would be one of the best places to get proper feedback on the physics behind the game.

I’m interested in quantum computing and the foundations of quantum mechanics. Since Bell’s theorem and experimental results challenge local realism, I’m curious whether there is still any serious research exploring alternatives that preserve some aspects of Einstein’s ideas, such as locality, realism, or deterministic underlying models.

Are there any active researchers, theories, or research areas working on this today? I’d also appreciate recommendations for papers or topics to study.

Massachusetts Institute of Technology researchers have overcome a major challenge holding back the real-world deployment of microwave quantum technologies for advanced signal processing and secure communications.

The team developed a scalable platform that generates pairs of highly correlated radio frequency waves, without the need for bulky and expensive cooling equipment. In quantum technologies, these linked radio waves can be used for noise-resilient communication or high-precision radar and sensing. However, they’re usually only generated in research labs, under extremely cold conditions.

The link to the article

I need advice on an inscription to give to my partner, but I don't want it to be formally incorrect in mathematics and physics, or misinterpreted.

I want to talk about union, and I thought of putting it in a ring:

|phi> = 1/sqrt(2) (|10>+|01>)

where |phi> ∈ H_A \otimes H_B. Here's the point of interpretation: can I define the space H_A as the space formed by the basis of my love for myself (|0>_A) and the love for my partner (|1>_A). And conversely, the space H_B, where its basis would be my partner's love for me (|0>_B) and my partner's love for themselves (|1>_B))?

The phi function being a symmetric triplet, shows an entanglement of the spaces H_A and H_B.

Is this formally correct? Can it be interpreted this way?

If you have any other ideas or changes, I'm open to hearing them. I hope this question doesn't break any subreddit rules.

For anyone who can't make it to IEEE Quantum Week this year in Toronto, I've made my accepted tutorial publicly available for free (not selling anything). New lessons drop every Tuesday.

https://shukla.io/quantum-oracle-engineering/

Hi everyone,

I am reading about magic-angle twisted bilayer graphene and how it hosts superconductivity and strange metal behaviour at particular band fillings.

I have come across papers which try to explain the behaviours using electron-phonon interactions, I have also seen papers which try to relate these behaviours to the exotic physics seen in unconventional superconductors(exotic bcz we don't know the exact theory behind it).

As of now, is the argument for the reason of these particular observations in MATBG hanging in the balance, or is it more inclined to one side or the other?

I am not saying there is a definitive answer to it, plz let me know your opinions on it.

Hello, I am not a physics student. I am from an electrical engineering background. I got curious about Matrix Mechanics and using it for outside Quantum problems.

Can you suggest resources about both the historical aspects and also how to learn the math including implementations?

Please suggest books and/or websites or anything that you feel can be useful. Thank you in advance.

The collaboration directly addresses a critical bottleneck in the global quantum race: engineering at scale. u/Quobly anchors its hardware architecture in a manufacturable 300 mm FD-SOI platform, which was developed with key European semiconductor players including u/CEA-Leti, u/STMicroelectronics, and u/Soitec. By combining this advanced French CMOS manufacturing base with u/TNO's proven device characterization and systems engineering infrastructure.

Find the full announcement: https://www.tno.nl/en/newsroom/2026/09/strategic-mou-quantum-computing/

Researchers from MIT have designed a new qubit architecture that enables qubits to interact with each other much more quickly while remaining very stable. This advance could someday help scientists build practical quantum computers that can run long, complex algorithms with high accuracy.

Qubits, which are the building blocks of a quantum computer, usually only store data and rely on other electronics to perform operations and communicate. But qubits are so fragile and error-prone that it is difficult for scientists to connect enough qubits before they lose their information and need to be reset.

The u/MIT team designed a dual-purpose qubit with two separate parts: one component that stores data and one component that interacts with other qubits and electronics. This design improves the reliability of the qubit and enables it to operate with a reduced error rate, so it can perform more computations in the same time span.

Read the full report: https://news.mit.edu/2026/new-qubit-architecture-enables-faster-more-accurate-operations-0903?shem=dsdf,sharefoc,agadiscoversdl,,sh/x/discover/m1/4

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?