The Concorde had throttles that were not mechanically linked, but electrically operated. This from the site concordesst.com:
The Aircraft has an electrically controlled throttle system that is used to control the power delivered from the engines. Moving the throttle leavers asks the computer to apply the power to the engines in a correct and controlled manner. Through throttle master controls on the overhead panel, each engine can be either connected to the throttle lever (main) to an alternate controller or not controlled at all.