4 papers
A Lie-algebraic Criterion for the Universality of Exponentiated Quantum Gates
Yinuo Xue, Qian Chen, Jing-Song Huang
We present a criterion that serves as the basis for a polynomial-time algorithm to decide whether a finite set of qudit gates exponentiated by some Hamiltonians is universal. Our a…
The complexity of semidefinite programs for testing -block-positivity
Qian Chen, Benoît Collins
We extend \cite{chen2025srkbp} by analyzing the complexity of the -block-positivity testing algorithm that stems from the optimization problem in Definition \ref{definition:SDP-…
Symmetry reduction for testing -block-positivity via extendibility
Qian Chen, Benoît Collins, Omar Fawzi
We study the problem of testing -block-positivity via symmetric -extendibility by taking the tensor product with a -dimensional maximally entangled state. We exploit the u…
Fields of definition for triangle groups as Fuchsian groups
Frank Calegari, Qiankang Chen
The compact hyperbolic triangle group admits a canonical representation to with discrete image which is unique up to conjugation. The trace…