Validation rule for Unique Product Name

I'm stumped and need some help. I'm trying to create a validation rule that requires the "Product Name" field on the "Product" object (not Opportunity Products) to be unique. When I try to create the rule I get a syntax error that the field doesn't exist. I'm probably missing something obvious.   

AND(
   NOT(ISBLANK(VLOOKUP(
    $ObjectType.Product2.Fields.Name,
    $ObjectType.Product2.Fields.Name, Name
   ))),
   OR(
     ISNEW(), 
     ISCHANGED(Name)
     )
)

#Trailhead Challenges