Tag Archives: Quantum computation

Some Questions from Recent Quantum Events

Posted on July 30, 2025 by Gil Kalai

Over the past few years, I have given several lectures about quantum computation, presenting my argument for why quantum computing—and even significant early milestones toward it—are fundamentally impossible. Recently, I participated in a debate with Matthias Christandl on the possibility … Continue reading →

Posted in Computer Science and Optimization, Controversies and debates, Physics, Quantum | Tagged , , | 6 Comments

Quantum Duel in Prague

Posted on May 20, 2025 by Gil Kalai

Later this evening on 18:00 Prague time there will be a debate between Matthias Christandl and me, about the possibility of quantum computation. The debate will be live-streamed on YouTube. The beautiful poster was designed by Helena Gráfová. Click here … Continue reading →

Posted in Computer Science and Optimization, Controversies and debates, Quantum | Tagged , | 5 Comments

The Case Against Google’s Claims of “Quantum Supremacy”: A Very Short Introduction.

Posted on December 9, 2024 by Gil Kalai

The 2019 paper “Quantum supremacy using a programmable superconducting processor”  asserted that Google’s Sycamore quantum computer,  with 53 qubits and a depth of 20, performed a specific computation in about 200 seconds. According to Google’s estimate, a state-of-the-art classical supercomputer … Continue reading →

Posted in Computer Science and Optimization, Physics, Quantum | Tagged , | 45 Comments

Amazing: Feng Pan and Pan Zhang Announced a Way to “Spoof” (Classically Simulate) the Google’s Quantum Supremacy Circuit!

Posted on March 10, 2021 by Gil Kalai

Feng Pan and Pan Zhang uploaded a new paper on the arXive  “Simulating the Sycamore supremacy circuits.” with an amazing announcement. Abstract: We propose a general tensor network method for simulating quantum circuits. The method is massively more efficient in … Continue reading →

Posted in Computer Science and Optimization, Physics, Quantum | Tagged , , | 14 Comments

Starting today: Kazhdan Sunday seminar: “Computation, quantumness, symplectic geometry, and information”

Posted on October 27, 2019 by Gil Kalai

Sunday, 27 October, 2019 – 14:00 to 16:00 Repeats every week every Sunday until Sat Feb 01 2020 Location: Ross 70 See also: Seminar announcement; previous post Symplectic Geometry, Quantization, and Quantum Noise. The Google supremacy claims are discussed (with … Continue reading →

Posted in Combinatorics, Computer Science and Optimization, Geometry, Physics, Teaching | Tagged , , , | 3 Comments

The Race to Quantum Technologies and Quantum Computers (Useful Links)

Posted on April 3, 2017 by Gil Kalai

One of my main research directions in the last decade is  quantum information theory and quantum computers. (See this post and this one.) It is therefore a pleasure to report and give many links on the massive efforts carried out these … Continue reading →

Posted in Computer Science and Optimization, Physics, Quantum | Tagged , , , , , | 18 Comments

Quantum computing: achievable reality or unrealistic dream

Posted on January 10, 2015 by Gil Kalai

  Michel Dyakonov’s View on QC                                     My view (based on Michel’s drawing*) Update: Alexander Vlasov’s view (based on Michel and Mikhail’s drawing) … Continue reading →

Posted in Quantum | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 7 Comments

Why Quantum Computers Cannot Work: The Movie!

Posted on March 18, 2014 by Gil Kalai

Update (April 2016) : Here is a link to a  new post on my May 2016 Notices AMS paper. Here are links to a videotaped lecture in two parts entitled “why quantum computers cannot work” recorded at the Simons Institute for … Continue reading →

Posted in Movies, Quantum | Tagged , , , | 123 Comments

BosonSampling and (BKS) Noise Sensitivity

Posted on August 1, 2013 by Gil Kalai

Update (Nov 2014): Noise sensitivity of BosonSampling and computational complexity of noisy BosonSampling are studied in this paper by Guy Kindler and me. Some of my predictions from this post turned out to be false. In particular the noisy BosonSampling … Continue reading →

Posted in Computer Science and Optimization, Physics, Probability, Quantum | Tagged , , , | 8 Comments

QSTART

Posted on April 12, 2013 by Gil Kalai

  Physics, Computer Science, Mathematics, and Foundations’ views on quantum information Inauguration conference for the Quantum Information Science Center (QISC), Hebrew university of Jerusalem Update: The news of our conference have made it to a big-league blog. Update (July 2013): QStart … Continue reading →

Posted in Applied mathematics, Computer Science and Optimization, Conferences, Physics | Tagged , , , , | 7 Comments