def test_dynamics(dissipation, dt, nsteps):
tentative_mpo = Mpo(band_limit_mol_list)
gs_mp = MpDm.max_entangled_gs(band_limit_mol_list)
# subtract the energy otherwise might cause numeric error because of large offset * dbeta
energy = Quantity(gs_mp.expectation(tentative_mpo))
mpo = Mpo(band_limit_mol_list, offset=energy)
tp = ThermalProp(gs_mp, mpo, exact=True, space="GS")
tp.evolve(None, 50, low_t.to_beta() / 2j)
gs_mp = tp.latest_mps
center_mol_idx = band_limit_mol_list.mol_num // 2
creation_operator = Mpo.onsite(
band_limit_mol_list, r"a^\dagger", mol_idx_set={center_mol_idx}
)
mpdm = creation_operator.apply(gs_mp)
mpdm_full = MpDmFull.from_mpdm(mpdm)
# As more compression is involved higher threshold is necessary
mpdm_full.compress_config = CompressConfig(threshold=1e-4)
liouville = SuperLiouville(mpo, dissipation)
r_square_list = [calc_r_square(mpdm_full.e_occupations)]
time_series = [0]
for i in range(nsteps - 1):
logger.info(mpdm_full)
mpdm_full = mpdm_full.evolve(liouville, dt)
r_square_list.append(calc_r_square(mpdm_full.e_occupations))
time_series.append(time_series[-1] + dt)
time_series = np.array(time_series)
if dissipation == 0:
assert np.allclose(get_analytical_r_square(time_series), r_square_list, rtol=1e-2, atol=1e-3)
else:
# not much we can do, just basic sanity check
assert (np.array(r_square_list)[1:] < get_analytical_r_square(time_series)[1:]).all()
def test_FT_dynamics_hybrid_TDDMRG_TDH(n_dmrg_phs, scheme):
mol_list = parameter_PBI.construct_mol(4, n_dmrg_phs, 10 - n_dmrg_phs).switch_scheme(scheme)
mpdm = MpDm.max_entangled_gs(mol_list)
tentative_mpo = Mpo(mol_list)
temperature = Quantity(2000, "K")
tp = ThermalProp(mpdm, tentative_mpo, exact=True, space="GS")
tp.evolve(None, 1, temperature.to_beta() / 2j)
mpdm = (
Mpo.onsite(mol_list, r"a^\dagger", mol_idx_set={0}).apply(tp.latest_mps).normalize(1.0)
)
mpdm.compress_config = CompressConfig(threshold=5e-4)
offset = mpdm.expectation(tentative_mpo)
mpo = Mpo(mol_list, offset=Quantity(offset, "a.u."))
# do the evolution
# nsteps = 90 # too many steps, may take hours to finish
nsteps = 40
dt = 10.0
occ = [mpdm.e_occupations]
for i in range(nsteps):
mpdm = mpdm.evolve(mpo, dt)
occ.append(mpdm.e_occupations)
# make it compatible with std data
occ = np.array(occ[:nsteps]).transpose()
with open(os.path.join(cur_dir, "FT_occ" + str(n_dmrg_phs) + ".npy"), "rb") as f:
std = np.load(f)
assert np.allclose(occ[:, :nsteps], std[:, :nsteps], atol=1e-3, rtol=1e-3)
def init_mps(self):
tentative_mpo = Mpo(self.model)
if self.temperature == 0:
gs_mp = Mps.ground_state(self.model, max_entangled=False)
else:
if self._defined_output_path:
gs_mp = load_thermal_state(self.model, self._thermal_dump_path)
else:
gs_mp = None
if gs_mp is None:
gs_mp = MpDm.max_entangled_gs(self.model)
# subtract the energy otherwise might cause numeric error because of large offset * dbeta
energy = Quantity(gs_mp.expectation(tentative_mpo))
mpo = Mpo(self.model, offset=energy)
tp = ThermalProp(gs_mp, mpo, exact=True, space="GS")
tp.evolve(None, max(20, len(gs_mp)), self.temperature.to_beta() / 2j)
gs_mp = tp.latest_mps
if self._defined_output_path:
gs_mp.dump(self._thermal_dump_path)
init_mp = self.create_electron(gs_mp)
energy = Quantity(init_mp.expectation(tentative_mpo))
self.mpo = Mpo(self.model, offset=energy)
logger.info(f"mpo bond dims: {self.mpo.bond_dims}")
logger.info(f"mpo physical dims: {self.mpo.pbond_list}")
init_mp.evolve_config = self.evolve_config
init_mp.compress_config = self.compress_config
if self.evolve_config.is_tdvp:
init_mp = init_mp.expand_bond_dimension(self.mpo)
init_mp.canonicalise()
return init_mp
def init_mps(self):
tentative_mpo = Mpo(self.mol_list)
if self.temperature == 0:
gs_mp = Mps.gs(self.mol_list, max_entangled=False)
if self.dissipation != 0:
gs_mp = MpDm.from_mps(gs_mp)
else:
gs_mp = MpDm.max_entangled_gs(self.mol_list)
# subtract the energy otherwise might cause numeric error because of large offset * dbeta
energy = Quantity(gs_mp.expectation(tentative_mpo))
mpo = Mpo(self.mol_list, offset=energy)
tp = ThermalProp(gs_mp, mpo, exact=True, space="GS")
tp.evolve(None, len(gs_mp), self.temperature.to_beta() / 2j)
gs_mp = tp.latest_mps
init_mp = self.create_electron(gs_mp)
if self.dissipation != 0:
init_mp = MpDmFull.from_mpdm(init_mp)
energy = Quantity(init_mp.expectation(tentative_mpo))
self.mpo = Mpo(self.mol_list, offset=energy)
logger.info(f"mpo bond dims: {self.mpo.bond_dims}")
logger.info(f"mpo physical dims: {self.mpo.pbond_list}")
if self.dissipation != 0:
self.mpo = SuperLiouville(self.mpo, self.dissipation)
init_mp.canonicalise()
init_mp.evolve_config = self.evolve_config
# init the compress config if not using threshold and not set
if self.compress_config.criteria is not CompressCriteria.threshold\
and self.compress_config.max_dims is None:
self.compress_config.set_bonddim(length=len(init_mp) + 1)
init_mp.compress_config = self.compress_config
# init_mp.invalidate_cache()
return init_mp
def test_mpo():
gs_dm = MpDm.max_entangled_gs(mol_list)
beta = Quantity(10, "K").to_beta()
tp = ThermalProp(gs_dm, Mpo(gs_dm.mol_list), exact=True, space="GS")
tp.evolve(None, 500, beta / 1j)
gs_dm = tp.latest_mps
mp = creation_operator.apply(gs_dm)
check_property(mp)
def init_mps_abs(self):
dipole_mpo = Mpo.onsite(self.mol_list, r"a^\dagger", dipole=True)
i_mpo = MpDm.max_entangled_gs(self.mol_list)
beta = self.temperature.to_beta()
tp = ThermalProp(i_mpo, self.h_mpo, exact=True, space="GS")
tp.evolve(None, 1, beta / 2j)
ket_mpo = tp.latest_mps
ket_mpo.evolve_config = self.evolve_config
a_ket_mpo = dipole_mpo.apply(ket_mpo, canonicalise=True)
a_ket_mpo.canonical_normalize()
a_bra_mpo = a_ket_mpo.copy()
return BraKetPairAbsFiniteT(a_bra_mpo, a_ket_mpo)
def test_bogoliubov():
# REF: JCP, 2016, 145, 224101
evolve_config = EvolveConfig(EvolveMethod.tdvp_ps)
# evolve_config = EvolveConfig()
omega = 1
D = 1
nlevel = 10
T = Quantity(1)
ph1 = Phonon.simple_phonon(Quantity(omega), Quantity(D), nlevel)
mol1 = Mol(Quantity(0), [ph1])
mlist = MolList([mol1] * 2, Quantity(1), scheme=4)
mpdm1 = MpDm.max_entangled_gs(mlist)
mpdm1.evolve_config = evolve_config
mpo1 = Mpo(mlist)
tp = ThermalProp(mpdm1, mpo1, exact=True)
tp.evolve(nsteps=20, evolve_time=T.to_beta() / 2j)
mpdm2 = tp.latest_mps
e1 = mpdm2.expectation(mpo1)
mpdm3 = (Mpo.onsite(mlist, r"a^\dagger", False, {0})
@ mpdm2).expand_bond_dimension(mpo1)
es1 = [mpdm3.e_occupations]
for i in range(40):
mpdm3 = mpdm3.evolve(mpo1, 0.1)
es1.append(mpdm3.e_occupations)
theta = np.arctanh(np.exp(-T.to_beta() * omega / 2))
ph2 = Phonon.simple_phonon(Quantity(omega), Quantity(D * np.cosh(theta)),
nlevel)
ph3 = Phonon.simple_phonon(Quantity(-omega), Quantity(-D * np.sinh(theta)),
nlevel)
mol2 = Mol(Quantity(0), [ph2, ph3])
mlist2 = MolList([mol2] * 2, Quantity(1), scheme=4)
mps1 = Mps.gs(mlist2, False)
mps1.evolve_config = evolve_config
mpo2 = Mpo(mlist2)
e2 = mps1.expectation(mpo2)
mps2 = (Mpo.onsite(mlist2, r"a^\dagger", False, {0})
@ mps1).expand_bond_dimension(mpo2)
es2 = [mps2.e_occupations]
for i in range(20):
mps2 = mps2.evolve(mpo2, 0.2)
es2.append(mps2.e_occupations)
assert np.allclose(es1[::2], es2, atol=5e-3)
def test_mpdm_full(nmols, phonon_freq):
ph = Phonon.simple_phonon(Quantity(phonon_freq), Quantity(1), 2)
m = Mol(Quantity(0), [ph])
mol_list = MolList([m] * nmols, Quantity(1))
gs_dm = MpDm.max_entangled_gs(mol_list)
beta = Quantity(1000, "K").to_beta()
tp = ThermalProp(gs_dm, Mpo(mol_list), exact=True, space="GS")
tp.evolve(None, 50, beta / 1j)
gs_dm = tp.latest_mps
assert np.allclose(gs_dm.e_occupations, [0] * nmols)
e_gs_dm = Mpo.onsite(mol_list, r"a^\dagger",
mol_idx_set={0}).apply(gs_dm, canonicalise=True)
assert np.allclose(e_gs_dm.e_occupations, [1] + [0] * (nmols - 1))
mpdm_full = MpDmFull.from_mpdm(e_gs_dm)
assert np.allclose(mpdm_full.e_occupations, e_gs_dm.e_occupations)
assert np.allclose(mpdm_full.ph_occupations,
e_gs_dm.ph_occupations,
rtol=1e-3)
def init_mps(self):
beta = self.temperature.to_beta()
self.h_mpo = Mpo(self.mol_list)
if self.spectratype == "abs":
dipole_mpo = Mpo.onsite(self.mol_list, r"a^\dagger", dipole=True)
i_mpo = MpDm.max_entangled_gs(self.mol_list)
tp = ThermalProp(i_mpo, self.h_mpo, exact=True, space='GS')
tp.evolve(None, 1, beta / 2j)
ket_mpo = tp.latest_mps
else:
impo = MpDm.max_entangled_ex(self.mol_list)
dipole_mpo = Mpo.onsite(self.mol_list, "a", dipole=True)
if self.job_name is None:
job_name = None
else:
job_name = self.job_name + "_thermal_prop"
impo.compress_config = self.compress_config
tp = ThermalProp(impo,
self.h_mpo,
evolve_config=self.evolve_config,
dump_dir=self.dump_dir,
job_name=job_name)
self._defined_output_path = tp._defined_output_path
if tp._defined_output_path:
try:
logger.info(
f"load density matrix from {self._thermal_dump_path}")
ket_mpo = MpDm.load(self.mol_list, self._thermal_dump_path)
logger.info(f"density matrix loaded: {ket_mpo}")
except FileNotFoundError:
logger.debug(f"no file found in {self._thermal_dump_path}")
tp.evolve(None, self.insteps, beta / 2j)
ket_mpo = tp.latest_mps
ket_mpo.dump(self._thermal_dump_path)
self.a_ket_mpo = dipole_mpo.apply(ket_mpo, canonicalise=True)
self.cv_mpo = Mpo.finiteT_cv(self.mol_list,
1,
self.m_max,
self.spectratype,
percent=1.0)
self.cv_mps = self.cv_mpo
def init_b_mpo(self):
# get the right hand site vector b, Ax=b
# b = -eta * dipole * \psi_0
# only support Holstien model 0/1 exciton manifold
beta = self.temperature.to_beta()
if self.spectratype == "abs":
dipole_mpo = Mpo.onsite(self.model, r"a^\dagger", dipole=True)
i_mpo = MpDm.max_entangled_gs(self.model)
tp = ThermalProp(i_mpo, self.h_mpo, exact=True, space='GS')
tp.evolve(None, 1, beta / 2j)
ket_mpo = tp.latest_mps
elif self.spectratype == "emi":
dipole_mpo = Mpo.onsite(self.model, "a", dipole=True)
if self._defined_output_path:
ket_mpo = \
load_thermal_state(self.model, self._thermal_dump_path)
else:
ket_mpo = None
if ket_mpo is None:
impo = MpDm.max_entangled_ex(self.model)
impo.compress_config = self.compress_config
if self.job_name is None:
job_name = None
else:
job_name = self.job_name + "_thermal_prop"
tp = ThermalProp(impo,
self.h_mpo,
evolve_config=self.evolve_config,
dump_dir=self.dump_dir,
job_name=job_name)
tp.evolve(None, self.insteps, beta / 2j)
ket_mpo = tp.latest_mps
if self._defined_output_path:
ket_mpo.dump(self._thermal_dump_path)
else:
assert False
ket_mpo = dipole_mpo.apply(ket_mpo.scale(-self.eta))
return ket_mpo, None
def test_ft():
model = get_model()
mpo = Mpo(model)
impdm = MpDm.max_entangled_gs(model)
impdm.compress_config = CompressConfig(threshold=1e-6)
temperature = Quantity(3)
evolve_config = EvolveConfig(adaptive=True, guess_dt=-0.001j)
tp = ThermalProp(impdm, mpo, evolve_config=evolve_config)
tp.evolve(nsteps=1, evolve_time=temperature.to_beta() / 2j)
mpdm = tp.latest_mps
mpdm = Mpo(model, Op("sigma_x", "spin")).contract(mpdm)
mpdm.evolve_config = EvolveConfig(adaptive=True, guess_dt=0.1)
time_series = [0]
sigma_z_oper = Mpo(model, Op("sigma_z", "spin"))
spin = [mpdm.expectation(sigma_z_oper)]
for i in range(29):
dt = mpdm.evolve_config.guess_dt
mpdm = mpdm.evolve(mpo, evolve_dt=dt)
time_series.append(time_series[-1] + dt)
spin.append(mpdm.expectation(sigma_z_oper))
qutip_res = get_qutip_ft(model, temperature, time_series)
assert np.allclose(qutip_res, spin, atol=1e-3)
def test_ft():
mol = get_mol()
mol_list = MolList([mol], Quantity(0))
mpo = Mpo(mol_list)
impdm = MpDm.max_entangled_gs(mol_list)
impdm.compress_config = CompressConfig(threshold=1e-6)
impdm.use_dummy_qn = True
temperature = Quantity(3)
evolve_config = EvolveConfig(adaptive=True, guess_dt=-0.001j)
tp = ThermalProp(impdm, mpo, evolve_config=evolve_config)
tp.evolve(nsteps=1, evolve_time=temperature.to_beta() / 2j)
mpdm = tp.latest_mps
mpdm = Mpo.onsite(mol_list, r"sigma_x").contract(mpdm)
mpdm.evolve_config = EvolveConfig(adaptive=True, guess_dt=0.1)
time_series = [0]
spin = [1 - 2 * mpdm.e_occupations[0]]
for i in range(30):
dt = mpdm.evolve_config.guess_dt
mpdm = mpdm.evolve(mpo, evolve_dt=dt)
time_series.append(time_series[-1] + dt)
spin.append(1 - 2 * mpdm.e_occupations[0])
exact = get_exact_ft(mol, temperature, time_series)
assert np.allclose(exact, spin, atol=1e-3)
