The promise of topological quantum computer – which would be resistant to errors because it would encode quantum information using trajectories of weird “quasiparticles” called anyons – is one of the main motivations why people investigate topological orders like fractional quantum Hall effect or spin liquids. The catch about this study is that, as far as I understand, it lacks the required stability, which arises from the fact that the topological order is exhibited by the ground state of the system (lowest energy), and the anyons are lowest excitations (lowest energies above the ground state). Here, as far as I understand, the topologically ordered state was created inside a quantum computer, with no reference to energy. Still, this is one step closer to realizing topological quantum computation. Also, the study uses quantum gates based both on anyon braiding – “winding” their trajectories around each other – and “fusion”, i.e. merging anyons with each other. I was not aware you can use fusion in this way.
I am still alive, and there are big news for the project – news that are over one month overdue, but I was so focused on writing grant proposals that I couldn’t find time to write about it. Long story short: we finished the preprint of our spin liquid paper (https://arxiv.org/pdf/2512.05630). This work originated much before I came to Darrick Chang’s group, thus I am only a third author, but I did my part within the QUINTO project.
What is it about? Basically, atoms can make photons interacting with each other. In general, the interaction of many simple objects can lead to unusual, counterintuitive behavior. For example, many interacting electrons can form fractional quantum Hall states, and many interacting spins can form spin liquids – both being complicated quantum states, whose unusual properties manifest themselves with emergence of “quasiparticles” – objects that behave like individual particles, although in reality they are collective states of many particles. These quasiparticles can behave unlike any elementary particle found in nature – for example, they can have a fraction of single electron charge, and be neither bosons nor fermions but “anyons”. In the paper, we ask: can we observe similar effects with atoms and light?
This completes an important milestones in our program researching applications of double-bracket flows to quantum computing.
If you read the paper, I encourage you to think of it as a new proof technique for showing that Grover's circuit ansatz can be used for any hermitian matrix H.
If you will use the paper, I encourage you to complain to e.g. me if something does not seem to perform well because knowing particularly hard instances would be valuable for us to improve on the theory.
If you will just glimpse through the paper, I encourage you to look at the numerics figure and locate the line of about 2k CZ gates which is roughly what Quantinuum can do.
We wouldn't have gotten past the 2nd round of review without the preexisting software #qrisp for quantum compilation functions. You can install qrisp via pip.
#introduction
Hello! I am Originalbarbas and I have recently joined this server. I am a physicist, currently researching #quantum technologies in #Vigo. I build things with lasers on them, basically. Sometimes I also build the lasers too. I have lived in many places, recently in #Scotland and #Catalunya.
🤔 What's the most improbable inconceivable thing that's going to happen in the next 5 years? Trying to only think of good things - we've had too many bad things since 2020.
A new global threat that pulls humanity together in a good way (by a mechanism known as the amity/enmity complex - which has AFAIK never been tested at a global level)
https://hamishcampbell.com/wp-content/uploads/2025/11/img_20251117_1813156325523248836446766-1024x768.jpgThis lecture was framed as leadership in a time of economic, social, and environmental crisis. In reality, it was a performance, a ritual reaffirmation of the system that generated those crises. A talk about “leadership” ...
No space, no time, no particles: A radical vision of quantum reality.
From @NewScientist: "If we admit that quantum numbers are the true essence of reality ... then a surprising and beautiful new vision of reality opens up to us."
"Nobel physics prize awarded to U.S.-based trio for discoveries in #quantum mechanics.
The award was given to Briton John Clarke, Frenchman Michel H. Devoret and American John M. Martinis for “experiments that revealed quantum physics in action,” the Royal Swedish Academy of Sciences said." https://www.nbcnews.com/world/europe/nobel-physics-prize-quantum-mechanics-rcna236082
Trio of physicists win Nobel Prize for revealing "bizarre properties" of the quantum world.
@CNN reports: "John Clarke, Michel Devoret and John Martinis will share the prize for their discovery of a phenomenon called quantum mechanical tunneling in an electrical circuit."
slajd o kocie schroedingera, z obrazkiem który powstał przez połączenie obrazków z głową kota żywego i martwego (albo obudzonego i śpiącego, nie wnikam), wygląda jak z kategorii "cursed AI"
Star Trek Discovery scene. Pictured is Paul Stammets (Adventures in Babysitting). He's in a crisp blue uniform, on a starship, and looking wistful. Closed caption reads, "I always wanted to converse with my mushrooms."
@nocontexttrek#startrek has come up in recent debates, as some scientists are now exploring the idea of human teleportation. So, you might want to take another look at the Heisenberg compensator, maybe it’s not entirely fictional anymore.
This makes Grover's algorithm no less exciting and makes ITE the more exciting.
Our derivation is based on the framework of double-bracket #quantum algorithms which systematically synthesise unitary circuits for Riemannian gradient flows on unitary manifolds with linear cost functions. Imaginary-time evolution happens to be a gradient flow, as we showed when proposing DB-QITE, and we use the backbone of DB-QSP proposed together with same team as on this paper I.e with Jeongrak Son Nelly Ng Bi Hong Tiang, Zoe Holmes and Yudai Suzuki. Yudai is not active here so I will remark about a few insights he shared with me during this project.
In the Grover case the Riemannian flow of ITE follows the geodesic. The velocity parametrization of the great circle geodesic realized by Grover's iterations, we get a nicely factoring tricks and arrive at a completely new formulation of running canonical formulation of QSP with Grover's oracle and diffusion operators implementing the processing. Yudai told me that there seems to be almost no useful signal functions for QSP that can be realized in the R-Z convention by Yoder, Low and Chuang. Well, apart from Grover that is, as we show towards the end of the paper. So this QSP convention suddenly comes into highlight through prominence of Grover's algorithm.
In summary Riemannian gradient flow is the most general structure, imaginary-time evolution is an example of that and if we want to make a quantum algorithm out of that then we formulate a double-bracket quantum algorithm - which comes out to be exactly Grover's algorithm 🐣
A meme based on a scene from The Office TV show. A corporate worker is asked to find a difference between two images. The one on the left says Grover's algorithm while the one on the left says imaginary-time evolution. The worker is in dismay over the futility of that beurocratic task as both are in fact the same.
Leadership in the Era of Quantum and AI – A Reaction
https://hamishcampbell.com/wp-content/uploads/2025/11/img_20251117_1813156325523248836446766-1024x768.jpgThis lecture was framed as leadership in a time of economic, social, and environmental crisis. In reality, it was a performance, a ritual reaffirmation of the system that generated those crises. A talk about “leadership” ...