---

name: dqmc-parameter-scans description: Set up systematic DQMC parameter studies across temperature, interaction strength U, or chemical potential mu. Use when doing temperature sweeps, phase diagram calculations, or any grid of simulations.

Parameter Scans

Generate a directory tree of simulation files (one directory per parameter point), then run with the queue system (see dqmc-run), then analyze (see dqmc-analyze).

Temperature Scan

Vary L while adjusting dt to maintain Trotter error bound:

Copyfrom dqmc_util import gen_1band_hub
import numpy as np

U = 4.0
step = 5  # L must be divisible by n_matmul and period_eqlt (defaults: 5)
for T in [0.1, 0.2, 0.5, 1.0]:
    beta = 1.0 / T
    dt = min((0.05/U)**0.5, beta / 10)
    L = int(np.ceil(beta / dt / step) * step)
    dt = beta / L

    gen_1band_hub.create_batch(
        prefix=f"data/T{T:.2f}/bin",
        Nfiles=4, Nx=6, Ny=6, U=U, dt=dt, L=L
    )

U-mu Scan

Grid over interaction strength and chemical potential:

Copyimport itertools
import numpy as np
from dqmc_util import gen_1band_hub

dt, L = 0.1, 40  # sets beta = L*dt
for U, mu in itertools.product([2, 4, 6, 8], np.linspace(-4, 4, 9)):
    gen_1band_hub.create_batch(
        prefix=f"data/U{U}_mu{mu:.1f}/bin",
        Nfiles=4, Nx=6, Ny=6, U=U, mu=mu, dt=dt, L=L
    )

Validation

• Directory structure created as expected
• Each directory has correct number of .h5 files

Tips

• Use descriptive directory names encoding key parameters
• Keep Nfiles >= 4 for reliable error estimates
• For large scans, generate files first, then run via queue system