Composite-type Rb-87 optical-pumping light source for the rubidium frequency standard

The light source is composed of a cylindrical Rb-87 lamp 10 mm diameter and a Rb-85 filter cell 3-7 mm long attached to the front flat face of the lamp. This composite type device is operated in an oven at about 100 C. Thus a light source for Rb-87 hyperfine optical pumping less than 4 cm long by 3 cm diameter was constructed

Exotic heavy-fermion superconductivity in atomically thin CeCoIn5 films

Funding: This work is supported by Grants-in-Aid for Scientific Research (KAKENHI) (Grants No. JP18H01180, No. JP18H05227, and No. JP18K03511) from Japan Society for the Promotion of Science (JSPS), and by Core Research for Evolutional Science and Technology (CREST) (Grant No. JP-MJCR19T5) from Japan Science and Technology Agency (JST).We report an in situ scanning tunneling microscopy study of atomically thin films of CeCoIn5, a d-wave heavy-fermion superconductor. Both hybridization and superconducting gaps are observed even in monolayer CeCoIn5, providing direct evidence of superconductivity of heavy quasiparticles mediated by purely two-dimensional bosonic excitations. In these atomically thin films, Tc is suppressed to nearly half of the bulk, but is similar to CeCoIn5/YbCoIn5 superlattices containing CeCoIn5 layers with the same thickness as the thin films. Remarkably, the out-of-plane upper critical field μ0Hc2⊥ at zero temperature is largely enhanced from those of bulk and superlattices. The enhanced Hc2⊥ well exceeds the Pauli and bulk orbital limits, suggesting the possible emergence of unusual superconductivity with parity mixing caused by the inversion symmetry breaking.Publisher PDFPeer reviewe

Exotic heavy-fermion superconductivity in atomically thin CeCoIn₅ films

We report an in situ scanning tunneling microscopy study of atomically thin films of CeCoIn5, a d-wave heavy-fermion superconductor. Both hybridization and superconducting gaps are observed even in monolayer CeCoIn5, providing direct evidence of superconductivity of heavy quasiparticles mediated by purely two-dimensional bosonic excitations. In these atomically thin films, Tc is suppressed to nearly half of the bulk, but is similar to CeCoIn5/YbCoIn5 superlattices containing CeCoIn5 layers with the same thickness as the thin films. Remarkably, the out-of-plane upper critical field μ0Hc2⊥ at zero temperature is largely enhanced from those of bulk and superlattices. The enhanced Hc2⊥ well exceeds the Pauli and bulk orbital limits, suggesting the possible emergence of unusual superconductivity with parity mixing caused by the inversion symmetry breaking