Crystal-field Paschen-Back effect on ruby in ultrahigh magnetic fields

Abstract

Zeeman spectra of the R lines of ruby (Cr 3+ : α-Al 2 O 3) were studied in ultrahigh magnetic fields up to 230 T by magnetophotoluminescence measurements. The observed Zeeman patterns exhibit nonlinear behaviors above 100 T, evidencing the breakdown of the previously reported Paschen-Back effect for B ⊥ c geometry. We adopted the crystal-field multiplet theory including the cubic crystal field (H cubic), the trigonal crystal field (H trig), the spin-orbit interaction (H SO), and the Zeeman interaction (H Z). It is found that the nonlinear splitting of the R lines is owing to the hybridization between the 2 E and 2 T1 states, which leads to the quantization of these Zeeman levels with the orbital angular momentum. Our results suggest that the exquisite energy balance among H cubic , H trig , H SO , and H Z realized in ruby offers a unique opportunity to observe the onset of the crystal-field Paschen-Back effect toward the high-field extreme.

Higher magnetic-field generation by a mass-loaded single-turn coil

“…Importantly, the present work shows that B max as well as t max can be increased for Φ8 and Φ6 STCs. At ISSP, the physical property measurements using the STC technique has been so far limited up to ∼240 T (using the Φ6 STC with the charging voltage of 50 kV) 25 . The proposed strategy using the mass-loading effect expands the potential of the STC technique and opens the door for higher-field science.…”

Ultra-slow electron spin-lattice relaxation in a low magnetic field enables massive optical spin polarization in the 4A2 ground state of Cr3+ in ruby*

“…For more than a century, ruby has been the subject of many experimental and theoretical investigations and has even been subjected to extreme experimental conditions such as a gigantic external magnetic field of 230 T [23] and titanic pressures up to ∼150 GPa [24,25]. Ruby has also been the subject of many investigations into electron spin-lattice relaxation in the 4 A 2 ground state and the 2 E excited state, both by theoretical and experimental studies [26][27][28][29].…”