Controlling superconductivity by tunable quantum critical points.
The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.
Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea.
S
S
Seo
Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea.
E
E
Park
Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
E D
ED
Bauer
Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
F
F
Ronning
Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, South Korea.
J N
JN
Kim
Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, South Korea.
J-H
JH
Shim
Condensed Matter and Magnet Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
J D
JD
Thompson
Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea.
Tuson
T
Park