Anisotropic magnetic-field response of quantum critical fluctuations in Ni-doped CeCoIn5
Anisotropic magnetic-field response of quantum critical fluctuations in Ni-doped CeCoIn5
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DOI：
10.1103/physrevb.99.054506
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发表时间：
2019-02
影响因子：
3.7
通讯作者：
M. Yokoyama;Kohei Suzuki;K. Tenya;Shota Nakamura;Y. Kono;S. Kittaka;Toshiro Sakakibara
中科院分区：
文献类型：
--
作者：
M. Yokoyama;Kohei Suzuki;K. Tenya;Shota Nakamura;Y. Kono;S. Kittaka;Toshiro Sakakibara
This paper demonstrates the anisotropic response of quantum critical fluctuations with respect to the direction of the magnetic field $B$ in Ni-doped ${\mathrm{CeCoIn}}_{5}$ by measuring the magnetization $M$ and specific heat $C$. The results show that $M/B$ at $B=0.1\phantom{\rule{4pt}{0ex}}\mathrm{T}$ for both the tetragonal $c$ and $a$ directions exhibits ${T}^{\ensuremath{-}\ensuremath{\eta}}$ dependencies, and that $C/T$ at $B=0$ follows a $\ensuremath{-}lnT$ function, which are the characteristics of non-Fermi-liquid (NFL) behaviors. For $B\phantom{\rule{0.16em}{0ex}}||\phantom{\rule{0.16em}{0ex}}c$, both the $M/B\ensuremath{\propto}{T}^{\ensuremath{-}\ensuremath{\eta}}$ and $C/T\ensuremath{\propto}\ensuremath{-}lnT$ dependencies change into nearly temperature-constant behaviors by increasing $B$, indicating a crossover from the NFL state to the Fermi-liquid state. For $B\phantom{\rule{0.16em}{0ex}}||\phantom{\rule{0.16em}{0ex}}a$, however, the NFL behavior in $C/T$ persists up to $B=7\phantom{\rule{4pt}{0ex}}\mathrm{T}$, whereas $M/B$ exhibits temperature-independent behavior for $B\ensuremath{\ge}1\phantom{\rule{4pt}{0ex}}\mathrm{T}$. These contrasting characteristics in $M/B$ and $C/T$ reflect the anisotropic nature of quantum critical fluctuations; the $c$-axis spin component significantly contributes to the quantum critical fluctuations. We compare this anisotropic behavior of the spin fluctuations to superconducting properties in pure ${\mathrm{CeCoIn}}_{5}$, especially to the anisotropy in the upper critical field and the Ising-like characteristics in the spin resonance excitation, and suggest a close relationship between them.
This paper demonstrates the anisotropic response of quantum critical fluctuations with respect to the direction of the magnetic field $B$ in Ni-doped ${\mathrm{CeCoIn}}_{5}$ by measuring the magnetization $M$ and specific heat $C$. The results show that $M/B$ at $B=0.1\phantom{\rule{4pt}{0ex}}\mathrm{T}$ for both the tetragonal $c$ and $a$ directions exhibits ${T}^{\ensuremath{-}\ensuremath{\eta}}$ dependencies, and that $C/T$ at $B=0$ follows a $\ensuremath{-}lnT$ function, which are the characteristics of non-Fermi-liquid (NFL) behaviors. For $B\phantom{\rule{0.16em}{0ex}}||\phantom{\rule{0.16em}{0ex}}c$, both the $M/B\ensuremath{\propto}{T}^{\ensuremath{-}\ensuremath{\eta}}$ and $C/T\ensuremath{\propto}\ensuremath{-}lnT$ dependencies change into nearly temperature-constant behaviors by increasing $B$, indicating a crossover from the NFL state to the Fermi-liquid state. For $B\phantom{\rule{0.16em}{0ex}}||\phantom{\rule{0.16em}{0ex}}a$, however, the NFL behavior in $C/T$ persists up to $B=7\phantom{\rule{4pt}{0ex}}\mathrm{T}$, whereas $M/B$ exhibits temperature-independent behavior for $B\ensuremath{\ge}1\phantom{\rule{4pt}{0ex}}\mathrm{T}$. These contrasting characteristics in $M/B$ and $C/T$ reflect the anisotropic nature of quantum critical fluctuations; the $c$-axis spin component significantly contributes to the quantum critical fluctuations. We compare this anisotropic behavior of the spin fluctuations to superconducting properties in pure ${\mathrm{CeCoIn}}_{5}$, especially to the anisotropy in the upper critical field and the Ising-like characteristics in the spin resonance excitation, and suggest a close relationship between them.