[12a-N405-1~7] 4.6 Terahertz Photonics

▲ [12a-N405-4] Terahertz Magnetospectroscopy of Gadolinium Gallium Garnet in Fields up to 25 T

〇(B)Junzhe Bao^1,2、Nicolas Marquez Peraca¹、Fuyang Tay^2,4、Elijah Kritzell^2,4、Xinwei Li²、Timothy Noe II²、Ikufumi Katayama⁵、Jun Takeda⁵、Hiroyuki Nojiri⁶、Hiroyasu Yamahara³、Hitoshi Tabata³、Andrey Baydin¹、Junichiro Kono^1,2,4,7 (1.Physics Rice Univ.、2.ECE Rice Univ.、3.UTokyo、4.SCI, Rice Univ.、5.Yokohama National U.、6.Tohoku Univ.、7.Material Rice Univ.)

キーワード：Gadolinium Gallium Garnet, THz spectroscopy, High magnetic field

Terahertz (THz) spectroscopy of solids in high magnetic fields can often provide new insight into the microscopic physics behind complex many-body behaviors. Advanced THz techniques and high magnetic field generation techniques are available, but the combination of the two has only been realized recently.
Here, we report results of THz magnetospectroscopy experiments on gadolinium gallium garnet (GGG), or Gd₃Ga₅O₁₂, in magnetic fields up to 25 T. GGG is a frustrated magnet, in which purely antiferromagnetic exchange interactions exist among Gd³⁺ ions located on two triangular sublattices. The frustration prevents ordering, and the system is best described as a spin liquid at low temperatures. However, an applied magnetic field (~1 T) produces an antiferromagnetic phase below 0.38 K. Microwave electron paramagnetic resonance (EPR) measurements on GGG have been performed, revealing a single line with g-factor around 2. However, the properties of GGG in high magnetic fields were previously unexplored.