Integrated quantum materials
Integrated quantum materials (iQM) such as microstructured crystals or two-dimensional materials embedded into electronic circuits, have enabled the observation of a host of intriguing quantum phases. The device integration affords incredible opportunities in design and in situ tunability, and brings these materials with properties like dissipationless transport and nonlinear responses a step closer toward applications.
In these quantum metamaterials, the emergent properties arise from the interplay between the microscopic interactions and device integration. The device edges and micropatterned dielectric environment of iQM result in the formation of self-cavities in the terahertz (THz) frequency range, the same energy scale as their quantum phases. To move from discovery to design, we need to better understand how these self-cavities and electromagnetic boundary conditions feed back into other degrees of freedom.
PC: Gunda Kipp
PC: Brad Baxley
On-chip THz electrodynamics
Fingerprints of underlying organizing principles of materials are captured in their interactions with light. As the wavelength of terahertz light, the energy scale resonant to many emergent phases, is much longer than typical device scales, we utilize on-chip THz circuitry to confine light into the near field, to the length scale of devices. In this way, we can probe the linear and nonlinear responses of iQM. For instance, we track properties such as the magnitude of insulating gaps, spectral weight magnitude, and collective mode frequency as a function of tuning parameter (like carrier density, displacement field, temperature, or magnetic field), within devices. In these circuits, we can also benchmark the optical properties against simultaneous DC transport. This multimodal information can be used to disentangle microscopic mechanisms from how the dielectric environment and microstructuring influences device properties.
Cavity control
The small size of devices relative to THz light has an additional benefit: low energy light can be easily confined into standing waves of current density, in collective, polaritonic (light-matter) modes. These modes act as cavities, enhancing light-matter interactions far beyond what is possible in the free space environment. We leverage this enhanced light matter interaction as a new control-axis in devices, seeking to understand how we can use structured and intentionally enhanced fluctuations of electromagnetic fields as a new route to create designer quantum materials.
PC: Brad Baxley
PC: Felix Sturm
THz tech
The new design-levers afforded by device integration, such as enhanced light-matter coupling and metamaterial engineering all possible on devices with terahertz and DC transport capabilities offers new opportunities for prototyping applications. In the group, we expand the capabilities of terahertz circuitry and work toward quantum-optics experiments on chip, moving toward using entanglement as a new quantum resource in the terahertz for both basic and applied applications.