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Shawn Geller

@shawngeller.bsky.social

Physicist at NIST Boulder, views are my own.

50 Posts137 Follower777 Folgt
Shawn Geller@shawngeller.bsky.social · 4mo ago

Our paper on the bunching behavior of bosons was published in PRA today! journals.aps.org/pra/abstract...

Measuring multiparticle indistinguishability with the generalized bunching probability

The indistinguishability of many bosons undergoing passive linear transformations followed by number basis measurements is fully characterized by the visible state of the bosons. However, measuring all the parameters in the visible state is experimentally demanding. In this work, we seek to perform partial characterization of the visible state by measuring properties of it that are available after randomization. First, we study the case where the occupied visible modes are randomly permuted, and second, we study the case where Haar random linear optical unitaries are applied. In each case, we find that the generalized bunching probability---which is the probability that all the input bosons arrive in a given subset of the output modes---obeys monotonicity with respect to some partial order of distinguishability of the input bosons. As an intermediate result, we show that Lieb's permanental-dominance conjecture for immanants is equivalent to the following statement: for states that are invariant under permutations of the occupied visible modes, the generalized bunching probability is maximized when the bosons are perfectly indistinguishable. We also prove that a consequence of the monotonicity of the generalized bunching probability after Haar averaging is that this average is maximized when the bosons are perfectly indistinguishable. Finally, we discuss applications of our results to thermometry of cold-atom systems.

journals.aps.org

Shawn Geller@shawngeller.bsky.social · 5mo ago

I’ll be at the APS meeting this week, our group has a few presentations that I’m excited about. Come hear Aliza Siddiqui talk about characterization of QEC cycles! summit.aps.org/smt/2026/eve..., Tue. March 17, 12:36 — 12:48 p.m. Mile High Ballroom 1C

A Diary of a Faulty Logical Qubit: Logical Gate Set Tomography | APS Meeting

The quantum characterization, verification, and validation (QCVV) toolbox assesses processor performance by analyzing their qubits and logic operations. One can construct a comprehensive model of quan...

summit.aps.org

Richard Kueng@richardkueng.bsky.social · 7mo ago

This year's Quantum Computing Theory in Practice Conference (QCTiP) is scheduled for 04/20/2026-04/25/2026 in Oxford, UK 🇬🇧: qctipconf.github.io Talk submission deadline is just round the corner: 01/11/2026. Looking forward to many exciting contributions and a great time in Hogwarts🪄, aehm Oxford🎓.

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Dulwich Quantum Computing@dulwichquantum.bsky.social · 7mo ago

The promise of solving the electronic structure of FeMo-co has long been central to the narrative that quantum computers will one day solve world hunger. Now we can finally put the "solving world hunger" part to test since Garnet Chan just solved FeMo-co *classically*! arxiv.org/abs/2601.04621

Classical solution of the FeMo-cofactor model to chemical accuracy and its implications

The main source of reduced nitrogen for living things comes from nitrogenase, which converts N2 to NH3 at the FeMo-cofactor (FeMo-co). Because of its role in supporting life, the uncertainty surroundi...

arxiv.org

The Guardian@theguardian.com · 10mo ago

American chess grandmaster Daniel Naroditsky dies at age 29

American chess grandmaster Daniel Naroditsky dies at age 29

* Naroditsky became a grandmaster in 2013 * No cause of death given in statement by family American chess grandmaster Daniel Naroditsky has died unexpectedly at the age of 29, his family said in a statement released by his club, the Charlotte Chess Center, on Monday. “It is with great sadness that we share the unexpected passing of Daniel Naroditsky,” the family said. “Daniel was a talented chess player, commentator, and educator, and a cherished member of the chess community.” Continue reading...

theguardian.com

Shawn Geller@shawngeller.bsky.social · 11mo ago

Excited to share our new paper! We prove that Lieb’s permanental dominance conjecture, which has been open for over half a century, is equivalent to a certain conjecture about the bunching behavior of bosons. arxiv.org/abs/2509.04550

Measuring Multiparticle Indistinguishability with the Generalized Bunching Probability

The indistinguishability of many bosons undergoing passive linear transformations followed by number basis measurements is fully characterized by its visible state. However, measuring all of the param...

arxiv.org