'Passengers are not allowed to enter Germany.
This does not apply to:
- nationals of Germany;
- passengers with permanent residence in Germany obtained before Coronavirus (COVID-19) or with a D-Visa issued by Germany;
- husband, wife, child and registered partner of nationals or residents of Germany;'

https://www.iatatravelcentre.com/int...1580226297.htm

It also appears that the quarantine on arrival may have been overturned by a court in Lower Saxony today but I believe that is currently a 'stay tuned' situation.