%0 Journal Article %1 sewani2020thermometry %A Sewani, V. K. %A Stohr, R. J. %A Kolesov, R. %A Vallabhapurapu, H. H. %A Simmet, T. %A Morello, A. %A Laucht, A. %B Physical Review B %D 2020 %K paramagnetic-resonance pi3 wrachtrup %R https://doi.org/10.1103/PhysRevB.102.104114 %T Spin thermometry and spin relaxation of optically detected Cr3+ ions in ruby Al2O3 %U https://journals.aps.org/prb/abstract/10.1103/PhysRevB.102.104114 %V 102 %X Paramagnetic ions in solid state crystals form the basis for many advanced technologies such as lasers, masers, frequency standards, and quantum-enhanced sensors. One of the most-studied examples is the Cr3+ ion in sapphire (Al2O3), also known as ruby, which has been intensely studied in the 1950s and 1960s. However, despite decades of research on ruby, some of its fundamental optical and spin properties have not yet been characterized at ultralow temperatures. In this paper, we present optical measurements on a ruby crystal in a dilution refrigerator at ultralow temperatures down to 20 mK. Analyzing the relative populations of its (4)A(2) ground-state spin levels, we extract a lattice temperature of 143 +/- 7mK under continuous laser excitation. We perform spin-lattice relaxation T-1 measurements in excellent agreement with the direct, one-phonon model. Furthermore, we perform optically detected magnetic resonance measurements showing magnetically driven transitions between the ground-state spin levels for various magnetic fields. Our measurements characterize some of ruby's low-temperature spin properties, and lay the foundations for more advanced spin control experiments. %Z Nt3agTimes Cited:0Cited References Count:34

@article{sewani2020thermometry, abstract = {Paramagnetic ions in solid state crystals form the basis for many advanced technologies such as lasers, masers, frequency standards, and quantum-enhanced sensors. One of the most-studied examples is the Cr3+ ion in sapphire (Al2O3), also known as ruby, which has been intensely studied in the 1950s and 1960s. However, despite decades of research on ruby, some of its fundamental optical and spin properties have not yet been characterized at ultralow temperatures. In this paper, we present optical measurements on a ruby crystal in a dilution refrigerator at ultralow temperatures down to 20 mK. Analyzing the relative populations of its (4)A(2) ground-state spin levels, we extract a lattice temperature of 143 +/- 7mK under continuous laser excitation. We perform spin-lattice relaxation T-1 measurements in excellent agreement with the direct, one-phonon model. Furthermore, we perform optically detected magnetic resonance measurements showing magnetically driven transitions between the ground-state spin levels for various magnetic fields. Our measurements characterize some of ruby's low-temperature spin properties, and lay the foundations for more advanced spin control experiments. }, added-at = {2020-11-04T14:51:03.000+0100}, annote = {Nt3agTimes Cited:0Cited References Count:34}, author = {Sewani, V. K. and Stohr, R. J. and Kolesov, R. and Vallabhapurapu, H. H. and Simmet, T. and Morello, A. and Laucht, A.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/211c7cf521554b44a503c4e3f2cc6b66b/shirschmann}, booktitle = {Physical Review B}, doi = {https://doi.org/10.1103/PhysRevB.102.104114}, interhash = {8ceeab345f0daa5352ebef9d27282ec2}, intrahash = {11c7cf521554b44a503c4e3f2cc6b66b}, issn = {2469-9950}, keywords = {paramagnetic-resonance pi3 wrachtrup}, series = 10, timestamp = {2020-11-04T13:53:30.000+0100}, title = {Spin thermometry and spin relaxation of optically detected Cr3+ ions in ruby Al2O3}, url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.102.104114}, volume = 102, year = 2020 }