Tanuj Khattar

Research Scientist @ Google Quantum AI

[Craig Gidney @CraigGidney]

As timelines tighten, details might benefit attackers more than defenders. So we're trying something weird: proving a circuit exists without revealing it.

For example, here's a zero-knowledge proof that we found 10x smaller quantum circuits for ECDLP: https://t.co/ypwPEVurg5

[Tanuj Khattar @tanujkhattar4]

@dallairedemers @CraigGidney We initially generated an SP1 STARK proof but then realized that STARK proofs in SP1 are not Zero Knowledge yet. Instead of moving to a different tool, we decided to generate a SNARK proof using SP1.

https://t.co/OG7ueFlJmf

[Craig Gidney @CraigGidney]

Been working on "Magic state cultivation: growing T states as cheap as CNOT gates" all year. It's finally out: https://t.co/VxQsZQJcDE

The reign of the T gate is coming to an end. It's now nearly the cost of a lattice surgery CNOT gate, and I bet there's more improvements yet.

[Tanuj Khattar @tanujkhattar4]

@pxmath24 @CraigGidney qpic is another open sourced tool to create quantum circuit diagrams in TikZ - https://t.co/poyUO1cPQV

You can checkout our implementation in Qualtran by downloading the source from https://t.co/avvi5fHIcX

[Tanuj Khattar @tanujkhattar4]

@pxmath24 @CraigGidney We implemented all our circuit decompositions using our open source quantum programming SDK https://t.co/Ao5VDcgpvI.

Qualtran provides tools to auto generate latex diagrams for "Bloqs" (aka quantum operations/circuits) and uses qpic under the hood.

[Tanuj Khattar @tanujkhattar4]

This table provides a nice summary of our constructions compared to the previous state of the art. In the sublinear ancila regime, we improved decompositions for generalized toffoli gate, incrementer, quantum-classical comparator and unary iteration.

[Tanuj Khattar @tanujkhattar4]

Checkout our latest paper where we provide new optimized constructions for a variety of fault tolerant gadgets.

For example: We can decompose an n-bit generalized Toffoli (MCX) using only 2n-3 Toffoli's in log(n) depth and 2 clean ancilla.

https://t.co/9bzU4lIQQZ

[Craig Gidney @CraigGidney]

It turns out that, often, clean workspace qubits can be used in a way that's "viral". Where you end up with more and more workspace that you can use as-if-it-was-clean. Very useful trick, found in parallel by several recent papers. https://t.co/M0MCHn4xZc

[Tanuj Khattar @tanujkhattar4]

Glad to see @skdh mentioning our work in her latest video, where she debunks myths about Quantum computers decoding national secrets in 2025!

[Sabine Hossenfelder @skdh]

Some recent headlines have been touting that Q-Day is coming potentially as soon as 2025. What is Q-Day? Well, it’s the day when quantum computers will be able to crack the current encryption protocols.

https://t.co/4YTtxpi7ie

[Tanuj Khattar @tanujkhattar4]

Come to my session today evening at 5:36pm to learn more about Qᴜᴀʟᴛʀᴀɴ!

[Google Quantum AI @GoogleQuantumAI]

It's day two of @APSphysics March Meeting!

Which session are you looking forward to the most?

[Tanuj Khattar @tanujkhattar4]

I'll also be at the Google booth (#1205) on Thursday morning 11:00am to talk about Qualtran!

[Google AI @GoogleAI]

Drop by the #APSMarch Google booth (#1205) today at 2:30pm to hear @tanujkhattar4 talk about Qᴜᴀʟᴛʀᴀɴ, a new open source library for effective resource estimation of fault tolerant quantum algorithms. Learn more at https://t.co/0WWBl9CbWJ

[Google Quantum AI @GoogleQuantumAI]

We’re at @APSphysics March Meeting this week! Attending? Stop by one of our 50+ sessions or swing by our booth to learn more and to chat with our team.

Read more about our presence and event schedule here ↓ https://t.co/Oah9YjB1AM

[Tanuj Khattar @tanujkhattar4]

@DulwichQuantum > Sprinkling some QAOA fairy dust onto something that doesn't work is not going to magically make it work.

This is the best one-line summary of this discussion that I've read so far!

[Tanuj Khattar @tanujkhattar4]

@NarendraHegade @dallairedemers @quantum_graeme @KikeSolanoPhys @DulwichQuantum @nmrqip @letonyo @JohnASmolin Indeed! We have open sourced our implementation of the original proposal and as discussed in our note, it wouldn't work even if you had a __perfect__ quantum optimizer (let alone QAOA / DCQF) -- this is because the claims via classical reductions don't hold true.

[Tanuj Khattar @tanujkhattar4]

@MarioKrenn6240 We simualted and open sourced the proposed algorithm. As we discuss in our note, it won't work even if you had a __perfect__ hypothetical quantum optimizer (instead of QAOA) -- because the claims via classical reductions in itself don't hold true!

See https://t.co/LjKDfqED8g

[Tanuj Khattar @tanujkhattar4]

Thank you Craig for the shoutout!

As we discuss in our note, the approach in the original paper doesn't work even if you had a _perfect_ quantum optimizer (instead of QAOA) -- this is because the claims via classical reductions in itself don't hold true!

[Craig Gidney @CraigGidney]

Remember that paper from the end of last year that claimed it could factor 2048 bit integers using 378 qubits? At the time, I mentioned to Tanuj Khattar that a nice starter paper would be to just simulate it and verify it doesn't work. Here's the result: https://t.co/894rHMLDWX

[Kevin Satzinger @KJSatz]

Thrilled to see our @GoogleQuantumAI paper on quantum error correction in @Nature today!

Check out this page for a video, blog posts by @sundarpichai and Julian Kelly, and the paper (free open access for everyone)

https://t.co/aQO07BZbQ3

[Dulwich Quantum Computing @DulwichQuantum]

Here is our takedown of the recent @TIME magazine article on quantum computing. 🧵
https://t.co/cmb2jj7fzj

[Kevin Satzinger @KJSatz]

I’m excited to share our latest work on quantum error correction. We’ve experimentally demonstrated the suppression of quantum errors by scaling a surface code logical qubit from distance-3 (17 qubits) to distance-5 (49 qubits). You can read it here: https://t.co/GpQJiMFQgm

[Google Quantum AI @GoogleQuantumAI]

Our work on quantum advantage in learning from experiments is now published in @ScienceMagazine!
Working with our Quantum Science Communicator @mccornut, @JarrodMcClean and @RobertHuangHY describe the results in this blog post: https://t.co/mRUCr1gCVJ

[Tanuj Khattar @tanujkhattar4]

@airvistara Thanks for the great service at Delhi Airport!! Would have almost missed my flight, had it not been for Ms Riya Patra.