Publication Date:
2017-03-10
Description:
Author(s): Yang-Zhi Chou, Yunxiang Liao, and Matthew S. Foster An exciting recent development is the ability to drive a quantum material into a highly excited, but still phase coherent state, using intense laser sources. Although such a state can be extremely short-lived, it can be long enough for detection using ultrafast spectroscopy. The authors here show how intense laser pulses can generate a new type of nonequilibrium superconducting phase. The authors demonstrate theoretically that the pump induces a “twisted” BCS state that subsequently evolves coherently after the cessation of the pulse. They show how the nonlinear coupling of the pump pulse light can induce coherent dynamics of Δ ( t ) , consistent with the experiment [R. Matsunaga et al. Phys. Rev. Lett. 111, 057002 (2013)]. Moreover, the authors show that more intense pump pulses can create a far-from-equilibrium phase of gapless superconductivity, originally predicted in the context of ultracold atomic gases. The terahertz pump is found to be much more efficient than the interaction quench at producing this gapless phase. These results open the door to engineering and observing new dynamical phases and phase transitions in quantum materials. [Phys. Rev. B 95, 104507] Published Wed Mar 08, 2017
Keywords:
Superfluidity and superconductivity
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
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