Electron-beam lithography system

Lange教授小组要求的电子束光刻系统（EBL）允许在太赫兹（THz）和中红外光谱范围内制造谐振器，从而能够在强亚波长尺度上控制电场和磁场的近场。通过定量的、无参数的数值模拟来裁剪太赫兹模式的近场，我们设计和制造了腔量子电动力学（c-QED）结构中的超强和深强光-物质耦合，以及近场增强谐振器，使原子强场的太赫兹实验成为可能。这种对电磁场的亚波长控制对于我们小组探索光-物质相互作用的极端极限起着核心作用，在这种情况下，光学非线性发生在明显短于光的单周期的时间尺度上。最近的研究重点包括动态Bloch振荡和高次谐波产生的观察，拓扑绝缘体中Dirac电子的光波加速，天线增强太赫兹近场中最小耗散自旋开关，可切换太赫兹谐振器中深强光物质耦合电子的非绝热控制，以及超强耦合共振的载波Rabi跳变的观察。典型的谐振腔结构沉积在承载电子激励的平面衬底上。我们通常制造尺寸在1到100微米之间的金属谐振器，特征尺寸小至50纳米。有效的远场耦合是通过将结构排列在多达106个元素的阵列中实现的。基于单天线的替代方法将强太赫兹场与光学探针脉冲相结合，提供了具有亚波长精度的独特高场实验室。所要求的系统将使我们能够继续这项研究并探索凝聚态系统中太赫兹亚周期物理的新方向。最近的c-QED实验利用光学谐振器的真空模式来控制电子输运、化学反应或超导性，达到平衡状态。相比之下，我们将研究在先前无法到达的耦合强度下相应的强场动力学，其中真空拉比频率超过载流子频率。为此，我们将通过先进的纳米结构进一步提高腔耦合朗道电子的耦合强度，研究超强耦合半导体子带间跃迁的非线性，并探索新的c-QED概念，包括超导谐振器或过渡金属二硫族化物等原子薄材料。从线性到非摄动非线性动力学的转变，我们期望揭示新的现象，包括高阶非线性，非经典光的产生，非线性相互作用产生的共振，或相变。同时，近场的亚波长和亚周期控制将在揭示相关量子动力学方面发挥关键作用。

The electron beam lithography system (EBL) requested by the group of Prof. Lange allows for the fabrication of resonators for the terahertz (THz) and mid-infrared spectral range, enabling control of electric and magnetic near fields on strongly subwavelength scales. Tailoring near fields of THz modes by quantitative, parameter-free numerical simulations, we design and fabricate ultrastrong and deep-strong light-matter coupling in cavity quantum electrodynamical (c-QED) structures, as well as near-field enhancing resonators enabling THz experiments with atomically strong fields. This subwavelength control of electromagnetic fields plays a central role for our group’s quest to investigate extreme limits of light-matter interaction in which optical nonlinearities occur on time scales significantly shorter than a single cycle of light. Recent research highlights include the observation of dynamical Bloch oscillations and high-harmonics generation, lightwave acceleration of Dirac electrons in topological insulators, minimally dissipative spin switching in antenna-enhanced THz near fields, non-adiabatic control of deep-strongly light-matter coupled electrons in switchable THz resonators, and the observation of carrier-wave Rabi flopping of ultrastrongly coupled resonances.Typical resonator structures are deposited on a planar substrate hosting an electronic excitation. We routinely fabricate metallic resonators measuring between 1 and 100 µm, with feature sizes down to 50 nm. Efficient far-field coupling is achieved by arranging the structures in arrays of up to 106 elements. Alternative approaches based on single antennas combine strong THz fields with optical probe pulses, providing a unique high-field laboratory with subwavelength precision. The requested system will allow us to continue this research and explore novel directions of THz subcycle physics in condensed-matter systems. Recent experiments in c-QED have utilized the vacuum modes of optical resonators to control electronic transport, chemical reactions, or superconductivity, in equilibrium. In contrast, we will investigate the corresponding strong-field dynamics at previously inaccessible coupling strengths, where the vacuum Rabi frequency exceeds the carrier frequency. To this end, we will further boost the coupling strength of cavity-coupled Landau electrons by advanced nanostructuring, investigate nonlinearities of ultrastrongly coupled semiconductor intersubband transitions, and explore novel c-QED concepts including superconducting resonators or atomically thin materials such as transition metal dichalcogenides. Transitioning from linear to non-perturbatively nonlinear dynamics, we expect to unveil novel phenomena including high-order nonlinearities, generation of non-classical light, resonances generated by nonlinear interactions, or phase transitions. Simultaneously subwavelength and subcycle control of near fields will play a key role in unravelling the relevant quantum dynamics.