Anticoncentration and State Design of Doped Real Clifford Circuits and Tensor Networks
Beatrice Magni, Markus Heinrich, Lorenzo Leone, Xhek Turkeshi
TL;DR
The paper analyzes anticoncentration and state design in real (orthogonal) Clifford circuits and tensor networks doped with magic and imaginary resources. By developing Weingarten calculus for the real Clifford group, it derives the orthogonal Clifford Porter-Thomas (OCPT) distribution and shows that real Matrix Product States and shallow local circuits reach this universal statistic at logarithmic depth, with bond dimension scaling polynomial in system size. It reveals a sharp resource hierarchy: polylogarithmic real or complex magic suffices to approximate Haar statistics, while a single imaginary state is enough to reproduce unitary Clifford statistics. These results provide a precise, resource-aware framework for achieving desired randomness properties in real-clifford-based quantum architectures and have implications for benchmarking and complexity in near-term devices.
Abstract
We investigate the statistical properties of orthogonal, or real, Clifford circuits doped with magic and imaginary resources. By developing the Weingarten calculus for the real Clifford group, we derive the exact overlap distribution of real stabilizer states, identifying a new universality class: the orthogonal Clifford Porter-Thomas distribution. We prove that local real architectures recover this global statistic in logarithmic depth. Furthermore, we uncover a sharp hierarchy in resource requirements: while retrieving Haar statistics necessitates a polylogarithmic amount of magic states, recovering the full unitary Clifford statistics requires only a single phase gate.
