FermionOp
25 views
Skip to first unread message
kardi...@googlemail.com
May 12, 2016, 7:35:48 PM5/12/16
to sympy
Hello,
I stumbled upon your project while searching for existing codes to deal with products of fermionic and bosonic operators. I am not quite familiar with Python programming, but I think I found an inconsistency in your code-base (not quite sure if this is fixed in secondquant). From a physical point of view powers of a fermionic operator other than op^1 do not make sense. From Pauli's exclusion principle one would expect something like a^n=S.Zero for n>=2 if a is any fermionic operator.
Another point inside sympy.physics.quantum.operatorordering:
Since one has the fermionic anticommutator-relation: Switching two 'independent' fermionic operators should switch the sign of the total expression, i.e. a*b = -b*a for any two independent fermionic operators a and b.
In addition to the aforementioned points I have implemented a few tweaks to your library to deal with indexed FermionOp's. I am just learning how to use git so I don't know how to properly set up pull requests. Nevertheless I would like to share my results.
Kind regars
Peter
I stumbled upon your project while searching for existing codes to deal with products of fermionic and bosonic operators. I am not quite familiar with Python programming, but I think I found an inconsistency in your code-base (not quite sure if this is fixed in secondquant). From a physical point of view powers of a fermionic operator other than op^1 do not make sense. From Pauli's exclusion principle one would expect something like a^n=S.Zero for n>=2 if a is any fermionic operator.
Another point inside sympy.physics.quantum.operatorordering:
Since one has the fermionic anticommutator-relation: Switching two 'independent' fermionic operators should switch the sign of the total expression, i.e. a*b = -b*a for any two independent fermionic operators a and b.
In addition to the aforementioned points I have implemented a few tweaks to your library to deal with indexed FermionOp's. I am just learning how to use git so I don't know how to properly set up pull requests. Nevertheless I would like to share my results.
Kind regars
Peter
Reply all
Reply to author
Forward
0 new messages