majoranaQ

◼ majoranaQ[c] returns True if c is a Majorana fermion operator.

◼ Operators are usually declared to be Majorana fermions using snegmajoranaoperators.

◼ For Majorana fermion operator c, conj[c]=c.

◼ For Majorana fermion operator c, c·c=1/2.

◼ Majorana operators anti-commute. Automatic reordering is performed using canonical ordering with respect to OrderedQ.

◼ Majorana operators are anti-commuted to the left of the (Dirac) fermionic operators. This allows for mixed Majorana-Dirac expressions.

◼ See also operatorQ.

Further examples

Load sneg and declare c to be a Majorana operator

<< sneg`sneg`;
snegmajoranaoperators[c]

Check that c is recognized as Majorana operator

majoranaQ[c]
operatorQ[c]
c[CR]
listmajoranaoperators

Rule for repeated operators

nc[c[], c[]]
nc[c[t], c[t]]

Automatic reordering

nc[c[2], c[1]]

Majorana operators are real, i.e. they are identical to their conjugates.

conj[c]

Mixed expressions

snegfermionoperators[d]
c[1]·d[CR]
d[CR]·c[1]