Scientific Author Ranking Services In the Economics profession, there is a free service called RePEc:

https://ideas.repec.org/

This service, amongst other things, ranks the top 5% of registered authors over a number of metrics (their publication number, citation, impact factor etc). 

I'm wondering whether other fields (e.g., biology, physics) have a similar service which ranks top contributors to their fields.

Many thanks.
Thomson Reuters does that for all fields: http://highlycited.com/.