Collective modes and short-time dynamics of the time-reversal symmety broken s+is superconductor
ORAL
Abstract
Motivated by the recent observation of the time-reversal symmetry broken
state in K-doped BaFe_2As_2 systems, we theoretically study the
collective modes and the short time dynamics of this state using an
effective four-band model with two hole and two electron pockets.
We consider the phase transition from s+- to s++ between the hole gaps
via an intermediate s+is state induced by hole doping. The transition
occurs, when the electron bands are incipient. As a result the
amplitude and phase modes are coupled giving rise to a variety of collective modes.
In particular, in the s+- state, we find the Higgs mode at frequencies similar to a two-band model with an
absent Leggett mode, while in the s+is and s++ state, we uncover a new coupled collective soft mode.
This mode becomes gapless at the boundaries between the s+is state and
the s+- and the s++ state, respectively.
state in K-doped BaFe_2As_2 systems, we theoretically study the
collective modes and the short time dynamics of this state using an
effective four-band model with two hole and two electron pockets.
We consider the phase transition from s+- to s++ between the hole gaps
via an intermediate s+is state induced by hole doping. The transition
occurs, when the electron bands are incipient. As a result the
amplitude and phase modes are coupled giving rise to a variety of collective modes.
In particular, in the s+- state, we find the Higgs mode at frequencies similar to a two-band model with an
absent Leggett mode, while in the s+is and s++ state, we uncover a new coupled collective soft mode.
This mode becomes gapless at the boundaries between the s+is state and
the s+- and the s++ state, respectively.
*The work of M.D. and P.S. was financially supported by National Science Foundation grant DMR-1506547
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Presenters
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Marvin Mueller
- Physics, Ruhr-Universität Bochum