Sending a thank you after a first round interview

I had an interview today and was told they were wrapping up first round interviews this week and looking to schedule second round interviews next week. Is it appropriate to send a thank you email afte

I had an interview today and was told they were wrapping up first round interviews this week and looking to schedule second round interviews next week. Is it appropriate to send a thank you email after this first round interview or should I wait to see if I make it to the next round? Also any tips on what to include in a thank you email are appreciated. Thanks!