Optical and microwave spectroscopy of Rydberg excitons in Cu$_2$O citations Optical and microwave spectroscopy of Rydberg excitons in Cu$_2$O2022-09-05https://www.teamwavelength.com/wp-content/uploads/logo_4.jpgWavelength Electronicshttps://www.teamwavelength.com/wp-content/uploads/logo_4.jpg200px200px