mirror of
https://github.com/triqs/dft_tools
synced 2024-12-26 22:33:48 +01:00
64 lines
1.6 KiB
Python
64 lines
1.6 KiB
Python
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from pytriqs.gf.local import *
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from pytriqs.plot.mpl_interface import *
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from numpy import *
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import os
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class IPTSolver:
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def __init__(self, **params):
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self.U = params['U']
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self.beta = params['beta']
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# Matsubara frequency
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self.g = GfImFreq(indices=[0], beta=self.beta)
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self.g0 = self.g.copy()
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self.sigma = self.g.copy()
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# Imaginary time
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self.g0t = GfImTime(indices=[0], beta = self.beta)
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self.sigmat = self.g0t.copy()
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def solve(self):
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self.g0t <<= InverseFourier(self.g0)
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self.sigmat <<= (self.U**2) * self.g0t * self.g0t * self.g0t
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self.sigma <<= Fourier(self.sigmat)
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# Dyson equation to get G
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self.g <<= inverse(inverse(self.g0) - self.sigma)
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# Parameters
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t = 0.5
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beta = 40
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n_loops = 20
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dos_files = []
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# Prepare the plot
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plt.figure(figsize=(6,6))
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plt.title("Local DOS, IPT, Bethe lattice, $\\beta=%.2f$"%(beta))
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# Main loop over U
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Umax=4.05
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Umin=0.0
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for U in arange(Umin, Umax, 0.51):
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# Construct the IPT solver and set initial G
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S = IPTSolver(U = U, beta = beta)
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S.g <<= SemiCircular(2*t)
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# Do the DMFT loop
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for i in range(n_loops):
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S.g0 <<= inverse( iOmega_n - t**2 * S.g )
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S.solve()
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# Get the real-axis with Pade approximants
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greal = GfReFreq(indices = [1], window = (-4.0,4.0), n_points = 400)
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greal.set_from_pade(S.g, 201, 0.0)
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r=(U-Umin)/(Umax-Umin) #for color
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oplot((-1/pi*greal).imag, lw=3,RI='S', color=(r,1.-r,1.-r), label = "U=%1.1f"%U)
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plt.xlim(-4,4)
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plt.ylim(0,0.7)
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plt.ylabel("$A(\omega)$");
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