snegfermionoperators

◼ snegfermionoperators[a,b,c] declares a, b, and c to be fermionic operators which obey canonical anti-commutation relations.

◼ By convention, the first index of the operator denotes the type of the operator (creation versus annihlation operator, see also CR and AN), while the last index corresponds to spin (see also UP and DO). If PrettyOutput is enabled, operators following this convention will be displayed with daggers and colored arrows for spin.

◼ For operator c tagged with snegfermionoperators, operatorQ[c]=True and fermionQ[c]=True.

◼ Operators have NHoldAll attribute.

◼ See also: fermionQ, operatorQ.

Further examples

Load sneg

<< sneg`sneg`;

Let c and d be a fermionic operator

snegfermionoperators[c, d]

Pretty printing of operators

c[CR]
c[AN]
c[CR, UP]
c[CR, DO]
c[CR, k, UP]
c[CR, k, σ]

Generate number operator for c

number[c[]]

List of all defined fermionic operators is stored in listfermionoperators.

listfermionoperators

NHoldAll attribute prevents N from acting on operator indexes.

N[Sqrt[2] c[CR, 1, UP]]