Thank you note after interview
If you feel that you want to thank members of the panel for their time and consideration, go on and send them a brief note. In my experience, it is usually impossible to exclude one or two people from the list without irritating someone, so I would say &mdash; write to all of them or none. It is natural to feel that a communication like this is "meaningless", "time-stealing" and "unnecessary" &mdash; long story short, it is not.  A senior academic receives a ton of spam and unrelated correspondence, which they delete with a grunt. Make your message short and positive, and they will delete it with a smile.