Putting greek letters in column names

Question

Is there any way to include Greek letters (α,β,γ) into column names of a matrix? i know you use :

colnames()<-c("column 1","column 2","column 3".....)

to add column names but when i tried to paste in the letters...

colnames(mymatrix)<-c("random name","parameters(α,β,γ)","parameters2(α,β,γ)")

it shows the "(α,β,γ)" as "(??,??,??)"

Does anyone know how to do this as i need it to be really obvious for reports at work