Linear Canonical-Ensemble Quantum Monte Carlo for Dilute Correlated Fermions

We present a finite‑temperature canonical‑ensemble determinant quantum Monte Carlo algorithm that enforces an exact fermion number and enables stable simulations of correlated lattice electrons. We propose a stabilized QR update that reduces the computational complexity from $O(\beta N^3)$ to $O(\beta N N_e^2)$, where $N$ is the system size and $N_e$ is the particle number. This yields a dramatic speedup in dilute regimes, opening unbiased access to large-scale simulations of strongly correlated low-density phases.