Dimension classification for small quantum circuits
Establish whether an exact dimension classification analogous to the classical SIZE(α·2^n/n) result holds for quantum circuit classes, for example by determining the PSPACE-dimension or GapP-dimension (or Hausdorff dimension) of BQSIZE(α·2^n/n) for α in [0,1].
References
It remains open whether a similar result holds for quantum circuits in either $PSPACE$-dimension or $GapP$-dimension (or even Hausdorff dimension).
                — Counting Martingales for Measure and Dimension in Complexity Classes
                
                (2508.07619 - Hitchcock et al., 11 Aug 2025) in Section 6.2, Quantum Circuit Complexity