Search found 10 matches

by lww
18 Jan 2022, 07:48
Forum: HowTos and FAQ for TeNPy
Topic: How to use random MPS to acess all ground states
Replies: 2
Views: 2254

Re: How to use random MPS to acess all ground states

Thanks, Johannes. By the way, what are your common practices to obtain the complete set of topologically degenerate ground states in tenpy? I know some states can be obtained by adiabatic flux insertion, but other states with non-Abelian statistics (e.g. 1412.8115 ) cannot be obtained in this way. C...
by lww
24 Dec 2021, 06:25
Forum: HowTos and FAQ for TeNPy
Topic: How to use random MPS to acess all ground states
Replies: 2
Views: 2254

How to use random MPS to acess all ground states

Hi, I was trying to obtain the two topologically degenerate ground states (easily distinguished by the symmetry of entanglement spectrum) of the lattice model detailed in 1208.2623 . According to the paper (also the published version), we have roughly equal chance to obtain each of these two states ...
by lww
30 Mar 2021, 04:31
Forum: HowTos and FAQ for TeNPy
Topic: How to deal with different ChargeInfos
Replies: 2
Views: 2038

Re: How to deal with different ChargeInfos

Thanks, Johannes! I'd like to know how to implement this by Array.iproject, resulting in a pure spin-1/2 MPS. It will be great if you can provide the code.
by lww
11 Mar 2021, 02:03
Forum: HowTos and FAQ for TeNPy
Topic: How to deal with different ChargeInfos
Replies: 2
Views: 2038

How to deal with different ChargeInfos

Given a MPS, I want to obtain the new MPS representing the projected state. For example, the original state lives in the space of spinful fermion with both particle number and Sz conservation, then it is mapped to spin system with Sz conservation by Gutzwiller projection 1-\left|0\right>\left<0\righ...
by lww
14 Jun 2019, 01:50
Forum: HowTos and FAQ for TeNPy
Topic: DMRG sweep problems
Replies: 5
Views: 5701

Re: DMRG sweep problems

I'll try adding a mixer to see whether it works. This also happens when the system setup is surely in FCI phase, so I suspect that I miss some parameter tweaks in tenpy. You once mentioned that arXiv:1407.6985 used an old version of tenpy, could you provide a link to the code? Thanks.
by lww
13 Jun 2019, 01:42
Forum: HowTos and FAQ for TeNPy
Topic: DMRG sweep problems
Replies: 5
Views: 5701

DMRG sweep problems

I recently did some calculations on fractional Chern insulator in infinite cylinder following 1208.2623 and noticed a recurrent sweep problem in iDMRG. Instead of gradually converging to ground state, the sweep process seems to jump between two distinct states as shown below. This sometimes happens ...
by lww
08 Apr 2019, 15:06
Forum: HowTos and FAQ for TeNPy
Topic: correlation length and charge sector
Replies: 1
Views: 2503

correlation length and charge sector

Correlation length in iDMRG is determined by the second largest eigenvalue \eta_2 of transfer matrix. I looked into the source code and found the following code, which always returns eigenvalues within charge sector 0. Does that mean we should always use \eta_2 from the same charge sector as dominan...
by lww
22 Mar 2019, 12:54
Forum: HowTos and FAQ for TeNPy
Topic: How to implement boundary pinning field in iDMRG appropriately?
Replies: 2
Views: 3301

Re: How to implement boundary pinning field in iDMRG appropriately?

Thank you for your instant reply! :D Specifically, I want to obtain the complete set of ground states in 2D following the route in this paper: https://arxiv.org/abs/1309.5669 . The authors obtained \psi_0 with conventional DMRG and found \psi_\nu with an anyon line threaded in by pinning one site at...
by lww
22 Mar 2019, 06:51
Forum: HowTos and FAQ for TeNPy
Topic: How to implement boundary pinning field in iDMRG appropriately?
Replies: 2
Views: 3301

How to implement boundary pinning field in iDMRG appropriately?

I need to create edge quasiparticles at both ends of the (infinite) cylinder geometry, to access topological sectors (with a little higher energy) unreachable via usual random initial states. I am not quite sure as of the standard way to do pinning in DMRG. Do I have to initialize an Engine and perf...
by lww
19 Mar 2019, 13:46
Forum: HowTos and FAQ for TeNPy
Topic: Twisted Boundary Conditions for a CouplingMPOModel
Replies: 3
Views: 4361

Re: Twisted Boundary Conditions for a CouplingMPOModel

I performed charge pumping by gradually adding twisted phase as required and using previously obtained GS as initial state in the next run, and the change ratio of averaged charge was unreasonably larger than expected. How should I do about the environments to get right results? Thanks! Update : Pro...