When exiting the airport, make sure you get out of the airport at exit to Switzerland (there is also an exit to France!).
By public transport
Take the bus number 50. Get off at bus stop Kannenfeldplatz and walk down the Metzerstrasse to the crossroad St. Johanns-Ring. Follow the St. Johanns-Ring down to the Klingelbergstrasse.
The charge for a taxi from the EuroAirport to the Department of Physics is of the order of CHF 30 (swiss francs).