Madan Ivan, Buh Jože, Baranov Vladimir V, Kabanov Viktor V, Mrzel Aleš, Mihailovic Dragan
Complex Matter Department, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
Center of Excellence on Nanoscience and Nanotechnology Nanocenter, Jamova 39, 1000 Ljubljana, Slovenia.
Sci Adv. 2018 Mar 30;4(3):eaao0043. doi: 10.1126/sciadv.aao0043. eCollection 2018 Mar.
Optical control of states exhibiting macroscopic phase coherence in condensed matter systems opens intriguing possibilities for materials and device engineering, including optically controlled qubits and photoinduced superconductivity. Metastable states, which in bulk materials are often associated with the formation of topological defects, are of more practical interest. Scaling to nanosize leads to reduced dimensionality, fundamentally changing the system's properties. In one-dimensional superconducting nanowires, vortices that are present in three-dimensional systems are replaced by fluctuating topological defects of the phase. These drastically change the dynamical behavior of the superconductor and introduce dynamical periodic long-range ordered states when the current is driven through the wire. We report the control and manipulation of transitions between different dynamically stable states in superconducting δ-MoN nanowire circuits by ultrashort laser pulses. Not only can the transitions between different dynamically stable states be precisely controlled by light, but we also discovered new photoinduced hidden states that cannot be reached under near-equilibrium conditions, created while laser photoexcited quasi-particles are outside the equilibrium condition. The observed switching behavior can be understood in terms of dynamical stabilization of various spatiotemporal periodic trajectories of the order parameter in the superconductor nanowire, providing means for the optical control of the superconducting phase with subpicosecond control of timing.
在凝聚态物质系统中，对呈现宏观相位相干的状态进行光学控制，为材料和器件工程开辟了引人入胜的可能性，包括光控量子比特和光致超导性。亚稳态在大块材料中通常与拓扑缺陷的形成有关，更具实际意义。缩小到纳米尺寸会导致维度降低，从根本上改变系统的性质。在一维超导纳米线中，三维系统中存在的涡旋被相位的波动拓扑缺陷所取代。当电流通过导线时，这些会极大地改变超导体的动力学行为，并引入动态周期性长程有序状态。我们报告了通过超短激光脉冲对超导δ-MoN纳米线电路中不同动态稳定状态之间的转变进行控制和操纵。不仅不同动态稳定状态之间的转变可以通过光精确控制，而且我们还发现了在近平衡条件下无法达到的新的光致隐藏状态，这些状态是在激光光激发准粒子处于非平衡条件时产生的。观察到的开关行为可以从超导体纳米线中序参量的各种时空周期性轨迹的动态稳定角度来理解，这为以亚皮秒级的时间控制对超导相进行光学控制提供了手段。
