Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 5: Transport: Quantum Coherence and Quantum Information Systems 1 (jointly with MA and HL)
TT 5.6: Vortrag
Montag, 26. März 2012, 10:45–11:00, BH 243
High cooperativity in a microwave resonator coupled to YIG — Hans Huebl1, •Johannes Lotze1, Christoph Zollitsch1,2, Fredrik Hocke1, Sebastian T. B. Goennenwein1, and Rudolf Gross1,2 — 1Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, Garching, Germany — 2Physik-Department, Technische Universität München, Garching, Germany
Understanding the coupling of magnetic moments (spins) to light fields (photons) on a quantum level is of fundamental interest. Recent work [1,2] on paramagnetic samples coupled to superconducting resonators has shown coherent coupling between microwave photons and electron spins. This coupling is enhanced compared to a single spin by a factor of √N, where N is the number of spins in the ensemble.
Here, we study a bulk ferrimagnetic Ga-doped yttrium iron garnet (YIG) crystal coupled to a superconducting niobium resonator operating at 6 GHz. Measuring the transmission through the resonator in a magnetic field, we observe an anticrossing of the spin and photon dispersions with a splitting of 450 MHz. Analyzing the magnetic field dependence of the resonance linewidths in this system in the interaction regime, we find that the coupling clearly dominates the intrinsic loss rates of the spin system and the resonator, an important requirement for studying the magnon-photon interaction in the strong coupling regime. The impact of microwave power and system temperature will be critically discussed.
D. I. Schuster et al., Phys. Rev. Lett. 105, 140501 (2010)
Y. Kubo et al., Phys. Rev. Lett. 105, 140502 (2010)