Search found 6 matches

by gopal
17 Mar 2021, 03:44
Forum: HowTos and FAQ for TeNPy
Topic: Energy gap for Odd and Even length
Replies: 2
Views: 2011

Re: Energy gap for Odd and Even length

Thank you for the suggestions. After I checked with ED and N being odd/even, I realized it is a physical effect. Now, I can interpret why it should be gapless or gapped depending on N. Most literature followed even L=N for the energy gap calculations in DMRG, so I wanted to make sure if it is relate...
by gopal
17 Mar 2021, 03:35
Forum: HowTos and FAQ for TeNPy
Topic: Exponentiation of operator / String order parameter
Replies: 11
Views: 58462

Re: Exponentiation of operator / String order parameter

Regarding the string correlation function, the documentation about correlation_function[https://tenpy.readthedocs.io/en/latest/reference/tenpy.networks.mps.MPS.html?highlight=correlation_function#tenpy.networks.mps.MPS.correlation_function]says that "if given as a list, opstr[r] is inserted at ...
by gopal
11 Mar 2021, 09:12
Forum: HowTos and FAQ for TeNPy
Topic: Energy gap for Odd and Even length
Replies: 2
Views: 2011

Energy gap for Odd and Even length

Hi, In the case of the Bose-Hubbard chain, while I calculated charged energy gap ( \Delta_c=E_0(N+1)+E_0(N-1)-2E_0(N) ) for L=even, I found the density waves regime as gapped. However, if we do the same calculation with L=odd ( the same even length+1), I found the energy gap as 0, sometimes negative...
by gopal
15 Feb 2021, 15:28
Forum: HowTos and FAQ for TeNPy
Topic: Entanglement_entropy for finite ladder
Replies: 2
Views: 2557

Re: Entanglement_entropy for finite ladder

Thanks for the reply. I was missing that cutting one bond will be enough.

by gopal
13 Jan 2021, 17:31
Forum: HowTos and FAQ for TeNPy
Topic: Entanglement_entropy for finite ladder
Replies: 2
Views: 2557

Entanglement_entropy for finite ladder

Hi, I want to calculate entanglement entropy in a finite two-leg ladder model, where the cutting bonds are two horizontal bonds in two legs. As an example, if I consider 6*2 lattice, and it is written in [0,1,2,3,.....11] in a zig-zag fashion, the bonds I want to cut are ( between 4 and 6) and (betw...
by gopal
22 Sep 2020, 06:59
Forum: HowTos and FAQ for TeNPy
Topic: Bond dimension is not increasing
Replies: 1
Views: 2036

Bond dimension is not increasing

Hi everyone, I am very new to Tensor Network as well as TenPy. I was trying to implement Bose-Hubbard model in a 2-leg ladder finite system, where there is tunnelling tt in between two leg. For that I have added this "self.add_coupling(-tt,0,'Bd',1,'B',0,plus_hc=True) " in the BoseHubbardM...