Yusuke Iguchi, Ph.D.

Pronunciation [yoo-sooh-keh ee-gooh-chee]

Contact

Email: yiguchi.phys@gmail.com

Experimental Condensed Matter Physicist

Former Senior Research Scientist at Stanford University

New Haven, Connecticut, USA

Education

PhD & MS in Basic Science (Condensed Matter Physics)
The University of Tokyo, Tokyo (2018) (Advisor: Yoshinori Onose)

BS in Physics
Tokyo University of Science, Tokyo (2013) (Advisor: Setsuo Mitsuda)

Teaching certificate for Science in middle & high schools, Tokyo University of Science (2013)

Employment history/work experience

2020 - 2026      Senior Research Scientist-Physical,
                           Geballe Laboratory for Advanced Materials,
                           Stanford University

2018 - 2020       JSPS Overseas Postdoctoral Research Fellow,
                           Applied Physics, Stanford University
                              (Advisor: Kathryn Ann Moler)  

2016 - 2018        JSPS Research Fellow (DC2),
                           Basic Science, The University of Tokyo

Honors and Awards

2026

• Physical Review B Editors' Suggestion

2024

• Physical Review B Editors' Suggestion

• Physical Review Letters Editors' Suggestion
• UJA Outstanding Paper Award
• Physical Review Materials Editors' Suggestion

2023

• Physical Review B Editors' Suggestion

2022

• Applied Physics Letters Editors' Pick

2018

• JSPS Overseas Research Fellowship

2017

• Journal of the Physical Society of Japan Editors' Choice

2016

• JSPS Research Fellowship for Young Scientists (DC2)

2015

• Outstanding Graduate Student Award, Graduate School of Arts and Sciences, The University of Tokyo

Selected Papers (All papers are here, all talks are here)

1. Magnetic edge fields in UTe$_2$ near zero background fields
   Y. Iguchi, H. Man, S. M. Thomas, F. Ronning, J. Ishizuka, M. Sigrist, P.F.S. Rosa, and K. A. Moler
   Physical Review B 110, 214505 (2024).

2. Anomalous superfluid density in a disordered charge density wave material: Pd-intercalated ErTe$_3$
   Y. Iguchi, J.A. Straquadine, C. Murthy, S.A. Kivelson, A. Singh, I.R. Fisher, and K.A. Moler
   Physical Review Letters 133, 036001 (2024) [Editors' Suggestion]

3. Superconducting vortices carrying a temperature-dependent fraction of the flux quantum
   Y. Iguchi, R. A. Shi, K. Kihou, C.-H. Lee, M. Barkman, A. L. Benfenati, V. Grinenko, E. Babaev, and K. A. Moler
   Science 380, 1244-1247 (2023)

4. Microscopic imaging homogeneous and single phase superfluid density in UTe$_2$
   Y. Iguchi, H. Man, S. M. Thomas, F. Ronning, P.F.S. Rosa, and K. A. Moler
   Physical Review Letters 130, 196003 (2023)
   

5. Local observation of linear-T superfluid density and anomalous vortex dynamics in URu$_2$Si$_2$
   Y. Iguchi, I. P. Zhang, E. D. Bauer, F. Ronning, J. R. Kirtley, K. A. Moler
   Physical Review B(Letter) 103, L220503 (2021)

6. Microwave non-reciprocity of magnon excitations in a non-centrosymmetric antiferromagnet Ba$_2$MnGe$_2$O$_7$
   Y. Iguchi, Y. Nii, M. Kawano, H. Murakawa, N. Hanasaki, and Y. Onose
   Physical Review B 98, 064416 (2018)

7. Magnetoelectrical control of nonreciprocal microwave response in a multiferroic helimagnet
   Y. Iguchi, Y. Nii, and Y. Onose
   Nature Communications 8, 15252 (2017)

8. Nonreciprocal magnon propagation in a noncentrosymmetric ferromagnet LiFe$_5$O$_8$
   Y. Iguchi, S. Uemura, K. Ueno, and Y. Onose
   Physical Review B 92, 184419 (2015) 

Teaching Experience

2025/2/4         Special Lecture for high school students, Teacher, JASS, Stanford
2024/4/2         Special Lecture for primary school students, Teacher, JASS, Stanford
2024/3/19        Special Lecture for high school students, Teacher, JASS, Stanford
2023/9/7         Special Lecture for senior students from Ritsumeikan Univ,Teacher, JASS, Stanford
2022/7             Girls Who Code in Japanese, Teacher, Japan
2022/5             nano@stanford, Guest Teacher at Greenleaf TK-8 School, CA
2021/12             Skype a Scientist, Guest Teacher at Chardon Primary School, NE
2013-2014         Material Science Exp. II/III, University of Tokyo, Japan, Teaching Assistant
Summer 2012   Physics I, Guest Teacher at Kumagaya High School, Japan

Professional and Leadership Activities

2024/12-current    Co-Director, United Japanese researchers Around the world (UJAW), USA

2024/1-current      Project Leader, Community Launching Support, WG-10,
United Japanese researchers Around the world (UJA), USA

2022/6-2026/5     Co-Founder & Organizer, Japanese Academic Seminars at Stanford, Stanford, CA

2024/9-2025/4     Vice Chair, North California, UJA Paper Award 2025

Visiting (short-term)

2019/1,   Max Planck Institute for Chemical Physics of Solids, Dresden, Germany (C. Hicks group)
2018/6,  Osaka University, Osaka, Japan (N. Hanasaki group)
2012/11,12, 2013/2, Photon Factory at KEK, Tsukuba, Japan (BL-3A, H. Nakao group)
2012/10,  SPring-8, Hyogo, Japan (BL-29XU, Y. Tanaka group)
2012/4,   National Institute for Materials Science, Tsukuba, Japan (N. Terada group)

Experimental skills

Measurements
Synchrotron X-Ray diffraction
Microwave spectroscopy(Low temperature Microwave broadband measurement in magnetic field/Design of microwave circuit/Micro Fabrication of Microwave circuit by using Photo- and EB-lithography)
Scanning SQUID microscopy
Ultra-low temperature measurement (Cryogenic dilution cryostat, Liquid He3/He4 cryostat)
Uniaxial strain measurement (Mechanical uniaxial stress/Micro uniaxial stress by piezo)

Sample growth
Polycrystal growth (EB, Spattering, Resistance heating)
Single crystal growth (Floating zone, Flux)

Others
Programing (Perl, Python, MATLAB)
Equipment Remote Control (Lab view, MATLAB, Python)
Radioactive material treatment (URu$_2$Si$_2$,UTe$_2$)

 Research Areas

Superconductivity and Quantum Materials

My research focuses on local magnetic imaging of superconducting states and emergent quantum phenomena using scanning SQUID microscopy. I have investigated unconventional superconductors, multiband superconductors, and strongly correlated quantum materials through measurements of magnetic penetration depth, vortex dynamics, and local magnetic responses.

Selected contributions include:

• Observation of unquantized vortices in the multiband superconductor K$_{0.77}$Ba$_{0.23}$Fe$_2$As$_2$ (Science, 2023).

• Local measurements of superfluid density in the odd-parity superconductor UTe$_2$, providing evidence against multiple superconducting phase transitions at ambient pressure (Physical Review Letters, 2023).
• Discovery of anomalous superfluid density near $T_c$ in the quasi-two-dimensional superconductor Pd$_x$ErTe$_3$₃, consistent with quantum phase fluctuations described by a quantum rotor model (Physical Review Letters, 2024).
• Observation of hidden magnetic fields through pinned vortices and antivortices in UTe$_2$ (Physical Review Letters, 2023).
• Studies of vortex dynamics in FeSe and URu$_2$Si$_2$ using local magnetic imaging (Physical Review B, 2019; Physical Review B, 2021).

Nonreciprocal Magnonics and Microwave Spectroscopy

During my Ph.D. at the University of Tokyo, I developed cryogenic microwave spectroscopy platforms operating up to 40 GHz and investigated nonreciprocal spin-wave propagation in non-centrosymmetric magnetic materials.

Selected contributions include:

• First observation of nonreciprocal microwave response arising from asymmetric magnon bands in chiral magnets (Physical Review B, 2015).

• Electrical and magnetic control of microwave nonreciprocity in multiferroic materials (Nature Communications, 2017; Applied Physics Letters, 2022).
• Quantitative observation of nonreciprocal microwave propagation in antiferromagnetic multiferroics (Physical Review B, 2018).

Frustrated Magnetism

As an undergraduate researcher, I studied spin-lattice coupling in geometrically frustrated magnets using synchrotron X-ray diffraction under uniaxial pressure.

• Revealed enhanced lattice responses near magnetic phase transitions in CuFeO$_2$ (Journal of the Physical Society of Japan, 2013).

Doctoral Dissertation

"Non-reciprocity of magnon excitations in non-centrosymmetric magnets" (doi/10.15083/00077865)