# NB

Current version does not suport bosons, i.e. NB must always be 0.

An integer representing the number of Bosons in the basis. For wavefunction psi, index 0 to psi.NF-1 refers to Fermions, index psi.NF to psi.NF+O.NB-1 refers to Bosons. Changing this number changes the wavefunction. If the new number of Bosons is smaller than the old number all modes referring to Bosons larger than NB-1 will be removed from the determinants.

## Example

We can define the function: $$|\psi\rangle = \left(\frac{1}{\sqrt{4}} a^{\dagger}_0 a^{\dagger}_1 + \frac{1}{\sqrt{4}} a^{\dagger}_0 a^{\dagger}_2 + (1+I)\frac{1}{\sqrt{4}} a^{\dagger}_1 a^{\dagger}_2 \right)|0\rangle,$$ changing the number of bosons in the basis from 0 to 2 currently results in an error.

### Input

Example.Quanty
NF=3
NB=0
psi = NewWavefunction(NF, NB, {{"110",sqrt(1/4)},{"101",sqrt(1/4)},{"011",(1+I)*sqrt(1/4)}})
print(psi.NB)
psi.NB=2

### Result

0
Error while executing the script:
/Users/haverkort/Documents/Quanty/Debuging/xcode.lua:9: Current version does not suport Bosons