Publications (11)
Phonon hydrodynamics and ultrahigh-room-temperature thermal conductivity in thin graphite
Yo Machida, Nayuta Matsumoto, Takayuki Isono +1
Allotropes of carbon, such as diamond and graphene, are among the best conductors of heat. We monitored the evolution of thermal conductivity in thin graphite as a function of temp…
Colossal Seebeck coefficient of hopping electrons in (TMTSF)PF
Yo Machida, Xiao Lin, Woun Kang +2
We report on a study of Seebeck coefficient and resistivity in the quasi-one-dimensional conductor (TMTSF)PF extended deep into the Spin-Density-Wave(SDW) state. The me…
Phonon hydrodynamics in bulk insulators and semi-metals
Yo Machida, Valentina Martelli, Alexandre Jaoui +2
Decades ago, Gurzhi proposed that if momentum-conserving collisions prevail among heat-carrying phonons in insulators and charge-carrying electrons in metals, hydrodynamic features…
Unstable Spin-Ice Order in the Stuffed Metallic Pyrochlore PrIrO
D. E. MacLaughlin, O. O. Bernal, Lei Shu +12
Specific heat, elastic neutron scattering, and muon spin rotation (SR) experiments have been carried out on a well-characterized sample of "stuffed" (Pr-rich) PrIr$_{2-…
Phonon hydrodynamic regimes in sapphire
Takuya Kawabata, Kosuke Shimura, Yuto Ishii +7
When an ideal insulator is cooled, four regimes of thermal conductivity are expected to emerge one after another. Two of these, the Ziman and the Poiseuille, are hydrodynamic regim…
Anisotropic B-T Phase Diagram of Non-Kramers System PrRh2Zn20
Taichi Yoshida, Yo Machida, Koichi Izawa +8
We have investigated the low temperature quadrupolar phenomena of the non-Kramers system PrRh2Zn20 under magnetic fields in the [100] and [110] directions. Our experiments reveal t…
Observation of Poiseuille Flow of Phonons in Black Phosphorus
Yo Machida, Alaska Subedi, Kazuto Akiba +5
The travel of heat in insulators is commonly pictured as a flow of phonons scattered along their individual trajectory. In rare circumstances, momentum-conserving collision events…
Magnetic Field Driven Electronic Singularities through Metamagnetic Phenomena: Case of the Heavy Fermion Antiferromagnet Ce(Ru0.92Rh0.08)2Si2
Yo Machida, Koichi Izawa, Dai Aoki +3
Thermoelectric power measurements on the heavy fermion antiferromagnet Ce(Ru0.92Rh0.08)2Si2 under magnetic field (H) show clearly that the antiferromagnetic state below the critica…
Phonon thermal Hall effect in a metallic spin ice
Taiki Uehara, Takumi Ohtsuki, Masafumi Udagawa +2
It has become common knowledge that phonons can generate thermal Hall effect in a wide variety of materials, although the underlying mechanism is still controversial. We study long…
Thermoelectric response across the semiconductor-semimetal transition in black phosphorus
Yuna Nakajima, Yuichi Akahama, Yo Machida
In spite of intensive studies on thermoelectricity in metals, little is known about thermoelectric response in semiconductors at low temperature. An even more fascinating and unans…
The phonon thermal Hall angle in black phosphorus
Xiaokang Li, Yo Machida, Alaska Subedi +3
The origin of phonon thermal Hall Effect (THE) observed in a variety of insulators is yet to be identified. Here, we report on the observation of a thermal Hall conductivity in a n…