Hi,all If I set the constraint quantum number to be Sz in the Kondo lattice model, but do not specify which type it is(spin or fermion), so does it mean that the conserved quantum number is the total Sz of Sz_spin + Sz_fermion? And if I set the type of constraint to be spin or fermion, in other orders, type="1" or type="0", then the conserved quantum number is the total Sz of spin or fermion?
While for quantum number N which only belongs to type="0" alternative fermion (SITEBASIS "spin" does not have it), then whether I specify the type or not in <CONSTRAINT >, the conserved quantum number shall always be the the total number of fermion.This is my understanding of this part of ALPS, and am I right?
Bo-Nan
On Mar 6, 2013, at 2:25 AM, Bo-Nan JIANG bonanjiang@gmail.com wrote:
Hi,all If I set the constraint quantum number to be Sz in the Kondo lattice model, but do not specify which type it is(spin or fermion), so does it mean that the conserved quantum number is the total Sz of Sz_spin + Sz_fermion?
Yes
And if I set the type of constraint to be spin or fermion, in other orders, type="1" or type="0", then the conserved quantum number is the total Sz of spin or fermion?
While for quantum number N which only belongs to type="0" alternative fermion (SITEBASIS "spin" does not have it), then whether I specify the type or not in <CONSTRAINT >, the conserved quantum number shall always be the the total number of fermion.This is my understanding of this part of ALPS, and am I right?
No, there are no types in constraints. If you want to restrict it to one particle type then you'll have to introduce a new quantum number.
Bo-Nan
-- Stay foolish,Stay hungry.
Dear all My goal is to calculate measures of entanglement (like negativity, concurrence and single site entropy) in DMRG. How is it possible in ALPS DMRG? Is there any way to have the reduced density matrix? In spin 1/2 the density matrix could be expressed in terms of pauli matrices, so the single site entropy could be calculated in an indirect way. But for negativity, specially for spin 1, I have no idea. Thank you kindly for your help in advance. Best Majid Abedi
Dear Majid Abedi I have evaluated negativity for spin 1-1/2 using DMRG! it is done by definition new operator in model.xml. it is better to calculated each part of negativity separately and then combine them.
On Thu, Mar 7, 2013 at 3:29 PM, Majid Abedi majabedi@yahoo.com wrote:
Dear all My goal is to calculate measures of entanglement (like negativity, concurrence and single site entropy) in DMRG. How is it possible in ALPS DMRG? Is there any way to have the reduced density matrix? In spin 1/2 the density matrix could be expressed in terms of pauli matrices, so the single site entropy could be calculated in an indirect way. But for negativity, specially for spin 1, I have no idea. Thank you kindly for your help in advance. Best Majid Abedi
Dear Hamid
Would you please give me more info about how to do it? What operators do you use to define your operator? best majid
--- On Sat, 9/3/13, hamid mosadegh hamid.mosadegh@gmail.com wrote:
From: hamid mosadegh hamid.mosadegh@gmail.com Subject: Re: [ALPS-users] Entanglement measures To: comp-phys-alps-users@lists.phys.ethz.ch Date: Saturday, 9 March, 2013, 5:22 PM
Dear Majid Abedi I have evaluated negativity for spin 1-1/2 using DMRG! it is done by definition new operator in model.xml. it is better to calculated each part of negativity separately and then combine them.
On Thu, Mar 7, 2013 at 3:29 PM, Majid Abedi majabedi@yahoo.com wrote:
Dear all My goal is to calculate measures of entanglement (like negativity, concurrence and single site entropy) in DMRG. How is it possible in ALPS DMRG? Is there any way to have the reduced density matrix?
In spin 1/2 the density matrix could be expressed in terms of pauli matrices, so the single site entropy could be calculated in an indirect way. But for negativity, specially for spin 1, I have no idea. Thank you kindly for your help in advance.
Best Majid Abedi
comp-phys-alps-users@lists.phys.ethz.ch