Dear sir,
I have tried the following code for a 3D system to calculate the peierls
phase but it shows the error
*- TypeError: only size-1 arrays can be converted to Python scalars. *
For 2D systems it is working fine*. *What should I do ?
import kwant
import numpy as np
from numpy import sin, cos, sqrt, pi
import scipy.sparse.linalg as sla
import matplotlib.pyplot as plt
import tinyarray as ta
import cmath
from cmath import exp
from matplotlib import pyplot as plt
sigma_z=ta.array([[1,0],[0,-1]])
sigma_x=ta.array([[0,1],[1,0]])
sigma_y=ta.array([[0,1j],[-1j,0]])
sigma_0=ta.array([[1,0],[0,1]])
def onsite(site):
return 2 * sigma_z
def hoppingx(site0, site1):
return - 0.5 * 1j * sigma_x
def hoppingy(site0, site1):
return - 0.5 * 1j * 1 * sigma_y
def hoppingz(site0, site1, peierls):
return (-0.5 * sigma_z) * peierls(site0, site1)
def make_system(a=1, L=10, W=20, H=10):
syst = kwant.Builder()
lat = kwant.lattice.cubic(norbs=2)
syst[(lat(x, y, z) for x in range(L) for y in range(W) for z in
range(H))] = onsite
syst[kwant.builder.HoppingKind((1, 0, 0), lat, lat)] = hoppingx
syst[kwant.builder.HoppingKind((0, 1, 0), lat, lat)] = hoppingy
syst[kwant.builder.HoppingKind((0, 0, 1), lat, lat)] = hoppingz
return syst
def make_lead(a=1, L=10, W=20):
lat = kwant.lattice.cubic(norbs=2)
lead = kwant.Builder(kwant.TranslationalSymmetry((0, 0, -a)))
lead[(lat(x, y, 0) for x in range(L) for y in range(W))] = onsite
lead[kwant.builder.HoppingKind((1, 0, 0), lat, lat)] = hoppingx
lead[kwant.builder.HoppingKind((0, 1, 0), lat, lat)] = hoppingy
lead[kwant.builder.HoppingKind((0, 0, 1), lat, lat)] = hoppingz
return lead
syst = make_system()
lead = make_lead().substituted(peierls='peierls_lead')
syst.attach_lead(lead)
#syst.attach_lead(lead.reversed())
syst = syst.finalized()
gauge = kwant.physics.magnetic_gauge(syst)
def B_syst(pos):
return np.exp(-np.sum(pos * pos))
peierls_syst, peierls_lead, peierls_lead = gauge(B_syst, B_syst)
params = dict(t=1, peierls=peierls_syst, peierls_lead=peierls_lead)
kwant.plotter.bands(syst.leads[0], momenta=np.linspace(-np.pi, np.pi, 200),
show=False, params=params)
plt.xlim(-np.pi, np.pi)
plt.ylim(-0.23, 0.23)
plt.xlabel('momentum [k_z]')
plt.ylabel('energy [E]')
plt.show()
On Fri, Jul 3, 2020 at 10:02 AM Naveen Yadav <[email protected]>
wrote:
> Dear sir,
> Thank you for the information. My 3d system have both first and second
> nearest neighbour hopping z-direction if I have a perpendicular magnetic
> field in x-direction. By choosing landau gauge (0,0,By). It is easy to add
> peierls phase to first nearest neighbour hopping in z-direction. Now my
> question is how should I add the peierls phase for the second neighbour
> hopping in z-direction?
>
> Best Regards
> Naveen Yadav
> Research Scholar
> Department of Physics & Astrophysics
> University of Delhi
> New Delhi-110007
>
> On Tue, Jun 30, 2020, 20:44 Naveen Yadav <[email protected]> wrote:
>
>> Dear sir,
>> Thank you for the information. My 3d system have both first and second
>> nearest neighbour hopping z-direction if I have a perpendicular magnetic
>> field in x-direction. By choosing landau gauge (0,0,By). It is easy to add
>> peierls phase to first nearest neighbour hopping in z-direction. Now my
>> question is how should I add the peierls phase for the second neighbour
>> hopping in z-direction?
>>
>> Best Regards
>> Naveen Yadav
>> Research Scholar
>> Department of Physics & Astrophysics
>> University of Delhi
>> New Delhi-110007
>>
>> On Tue, Jun 30, 2020, 19:49 Anton Akhmerov <[email protected]>
>> wrote:
>>
>>> Hi Naveen,
>>>
>>> That's mostly a convenience function. The same functionality, although
>>> at a bit of a lower level is available in Kwant 1.4, see here:
>>>
>>> https://kwant-project.org/doc/1/pre/whatsnew/1.4#automatic-peierls-phase-calculation
>>>
>>> Best,
>>> Anton
>>>
>>> On Sat, 27 Jun 2020 at 07:04, Naveen Yadav <[email protected]>
>>> wrote:
>>> >
>>> > Dear sir,
>>> > In the Kwant 1.5 documentation you have introduced
>>> kwant.bulider.add_peierls_phase(syst). Is this functionality ready to use
>>> by downloading the source code buider.py from gitlab?
>>> >
>>> > Best Regards
>>> > Naveen Yadav
>>> > Research Scholar
>>> > Department of Physics & Astrophysics
>>> > University of Delhi
>>> > New Delhi-110007
>>> >
>>> > On Fri, Jun 12, 2020, 15:42 Naveen Yadav <[email protected]>
>>> wrote:
>>> >>
>>> >> Ok sir, thank you.
>>> >>
>>> >> Best Regards
>>> >> Naveen Yadav
>>> >> Research Scholar
>>> >> Department of Physics & Astrophysics
>>> >> University of Delhi
>>> >> New Delhi-110007
>>> >>
>>> >> On Fri, Jun 12, 2020, 14:25 Anton Akhmerov <
>>> [email protected]> wrote:
>>> >>>
>>> >>> Dear Naveen,
>>> >>>
>>> >>> I fear you'll have to wait—it's not yet released.
>>> >>>
>>> >>> Best,
>>> >>> Anton
>>> >>>
>>> >>> On Fri, 12 Jun 2020 at 10:51, Naveen Yadav <[email protected]>
>>> wrote:
>>> >>> >
>>> >>> > Dear KWANT developers,
>>> >>> > I am not able to update KWANT 1.5
>>> >>> > How can I update it? Please advise.
>>> >>> >
>>> >>> >
>>> >>> > Best Regards
>>> >>> > Naveen Yadav
>>> >>> > Research Scholar
>>> >>> > Department of Physics & Astrophysics
>>> >>> > University of Delhi
>>> >>> > New Delhi-110007
>>>
>>
--
Best Regards,
Naveen Yadav
Research Scholar
Department of Physics & Astrophysics
University Of Delhi
New Delhi-110007
