I am a PhD student in the Theory Group at Columbia advised by Henry Yuen, and before that I was a graduate student at the Institute for Quantum Computing at the University of Waterloo, advised by John Watrous. I study theoretical computer science, with a focus on quantum computation.

My research is broadly about understanding fully-quantum tasks, including quantum cryptography, unitary complexity theory, and algorithms for learning from quantum data. Some specific problems that I think about are algorithms for shadow tomography, the complexity of unitary synthesis problems, and various topics in quantum cryptography like quantum money and pseudo-randomness. I am generally happy to talk about anything related to computer science, so if you have a question or idea please feel free to reach out to me!

Email: johnb at cs dot columbia dot edu

Selected Publications

For a full list of publications, click here.

• Separating QCMA from QMA with a classical oracle. John Bostanci, Jonas Haferkamp, Chinmay Nirkhe, and Mark Zhandry.
  [pdf, arXiv, eccc]

• Learning the closest product state. Ainesh Bakshi, John Bostanci, William Kretschmer, Zeph Landau, Jerry Li, Allen Liu, Ryan O’Donnell, and Ewin Tang.
  STOC 2025, QIP 2025 short plenary talk.
  [pdf, arXiv, slides]

• A General Duality for Representations of Groups with Applications to Quantum Money, Lightning, and Fire. John Bostanci, Barak Nehoran, and Mark Zhandry.
  STOC 2025, QIP 2025 contributed talk, QCrypt 2025 invited plenary talk.
  [pdf, arXiv, eprint]

• An efficient quantum parallel repetition theorem and applications. John Bostanci, Luowen Qian, Nicholas Spooner, Henry Yuen.
  STOC 2024, QIP 2024 short plenary talk.
  [pdf, arXiv, eprint, eccc, slides]

• Unitary Complexity and the Uhlmann Transformation Problem. John Bostanci, Yuval Efron, Tony Metger, Alexander Poremba, Luowen Qian, Henry Yuen.
  ITCS 2026, QIP 2024 long plenary talk.
  [pdf, arXiv]

Teaching

In Fall 2022 I was a TA for Introduction to Quantum Computing at Columbia, taught by Henry Yuen.

In Summer 2023 I was a TA for Topological Aspects of Error Correcting Codes at the Park City Mathematics Institute Graduate Summer School, taught by Jeongwan Haah. Click here to see the problem sets and solutions.

Work Experience

In the summer of 2024, I was an intern at NTT Research working with Mark Zhandry.

Miscellaneous

Here are the slides I used for my candidacy exam at Columbia.