Unusual orders in CeRh2As2
ORAL
Abstract
The heavy-fermion compound CeRh2As2 exhibits a complex phase diagram with rather unusual
states at low temperatures. A prominent example is multi-phase superconductivity[1]
which seems to develop inside a normal state whose order is still unclear.
Thermodynamic and magnetic measurements seem to indicate a non magnetic state with multipolar order,
antiferromagnetic (AFM) order, however, was clearly detected by μSR and NQR/NMR experiments. Recent
The present talk focusses on the instabilities of the strongly renormalized Fermi liquid
state in the heavy-fermion compound CeRh2As2. The narrow quasiparticle bands which arise from the Ce-4f degrees of freedom via the Kondo effect are calculated by means of the Renormalized Band (RB) method. A simplified model band structure is used to calculate the momentum-dependent multipolar susceptibilities. We conjecture that the Kondo-induced quasi-quartet CEF ground state [2] in combination with pronounced nesting features of the Fermi surface may give rise to ordered states involving multipolar degrees of freedom [3,4].
[1] S. Khim et al., Science 373, 1012 (2021).
[2] D. Christovam et al, Physics. Rev. Lett. 132, 046401 (2024)
[3] D. Hafner et al., Phys. RevX 12, 011023 (2022)
[4] P. Khanenko et al, arXiv:2409.11894
states at low temperatures. A prominent example is multi-phase superconductivity[1]
which seems to develop inside a normal state whose order is still unclear.
Thermodynamic and magnetic measurements seem to indicate a non magnetic state with multipolar order,
antiferromagnetic (AFM) order, however, was clearly detected by μSR and NQR/NMR experiments. Recent
The present talk focusses on the instabilities of the strongly renormalized Fermi liquid
state in the heavy-fermion compound CeRh2As2. The narrow quasiparticle bands which arise from the Ce-4f degrees of freedom via the Kondo effect are calculated by means of the Renormalized Band (RB) method. A simplified model band structure is used to calculate the momentum-dependent multipolar susceptibilities. We conjecture that the Kondo-induced quasi-quartet CEF ground state [2] in combination with pronounced nesting features of the Fermi surface may give rise to ordered states involving multipolar degrees of freedom [3,4].
[1] S. Khim et al., Science 373, 1012 (2021).
[2] D. Christovam et al, Physics. Rev. Lett. 132, 046401 (2024)
[3] D. Hafner et al., Phys. RevX 12, 011023 (2022)
[4] P. Khanenko et al, arXiv:2409.11894
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Presenters
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Gertrud Zwicknagl
Tech Univ Braunschweig
Authors
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Gertrud Zwicknagl
Tech Univ Braunschweig