1. Scientific idea and experimental setup
Coherent coupling between a ferromagnetic magnon and a superconducting qubit
Science 349, 405 (2015) by Y Tabuchi, S Ishino, A Noguchi, T Ishikawa, R Yamazaki, K Usami, Y Nakamura, Tokyo University
Motivation of the talk
Scientific idea and experimental setup
Experimental result and discussion
“In my dreams, I have a plan….” ABBA

2. Motivation
1. Microwave/optical conversion
2. “To get out of the fridge” (microwave superconducting qubits require housing in dilution fridges, while optical qubits can operate in room temperature)
3. Identify the R&D parts of industry that are interested in

3. A ferromagnetic magnon in YIG and a superconducting qubit (transmon)
f= GHz
f=8.488 GHz
f=8.136 GHz
Yttrium Iron Garnet
(YIG) sphere
m=NmB , N =1.4x1018

4. Coherent coupling between a ferromagnetic magnon and a superconducting qubit
Yttrium Iron Garnet
(YIG) sphere
m=NmB , N =1.4x1018
TE102 mode
f=8.488 GHz

5. The experimental setup
g – transmon-type superconducting qubit
f – YIG sphere glued to an aluminum-oxide rod
c – A pair of disc-shape neodymium permanent magnets, 0.29T in a gap of 4mm
e – superconducting coil of ~ 1.7 T/A,
d- a magnetic yoke made of iron

6. Measurement scheme

7. Coupling of magnons of Kittel mode to TE102
Strong coupling of 21 MHz between the magnons and TE102 mode

8. Static coupling of magnons and qubit
gqm=gmgq/D=10MHz, D=wq- wT102
Reflection at wT103

9. Dynamically tunable coupling between the qubit and the Kittel mode
gqm,p~Pd((wFMR+wq)/2)
wD=(wFMR+wq)/2

10. Dynamically tunable coupling between the qubit and the Kittel mode
gqm,p~Pd((wFMR+wq)/2)

11. Dynamically tunable coupling between the qubit and the Kittel mode
Experiment with a probe frequency close to wFMR

12. Conclusion
1. Coherent static coupling of qubit, magnons and resonator modes are demonstrated.
2. Parametric coupling is a demonstrated
3. Where the technology can be utilized: magneto-optical transducer?