Designing a Microsecond-Long On-Chip Microwave Delay Line Using SrTiO3 Dielectricity

The delay line is a fundamental circuit design component which slows down a signal with minimal attenuation to provide delay effects, with applications that include interferometry and signal filtering. Cryogenic superconducting delay lines can be less lossy than their regularly conducting counterparts. Scientists can engineer microwave photos with coherence times of several microseconds (us), longer than current on-chip delays. We utilize the high dielectric constant (\u3e10^4) of strontium titanate at cryogenic temperatures to slow own signal propagation on a coplanar waveguide. Here, we present a design for an on-chip 5 (us) superconducting delay line ad 5 GHz with small enough footprint to fit on-chip. This delay is more than 200 times longer than previously demonstrated while simultaneously more compact, enabling new regimes of interferometry. We also use simulations to characterize the sensitivity of the optimized design to alternative fabrication parameters. These designs may be useful for quantum information systems and integrated circuit design

Light-Induced Microwave Noise in Superconducting Microwave-Optical Transducers

Microwave-to-optical transducers are integral to the future of superconducting quantum computing, as they would enable scaling and long-distance communication of superconducting quantum processors through optical fiber links. However, optically-induced microwave noise poses a significant challenge in achieving quantum transduction between microwave and optical frequencies. In this work, we study light-induced microwave noise in an integrated electro-optical transducer harnessing Pockels effect of thin film lithium niobate. We reveal three sources of added noise with distinctive time constants ranging from sub-100 nanoseconds to milliseconds. Our results gain insights into the mechanisms and corresponding mitigation strategies for light-induced microwave noise in superconducting microwave-optical transducers, and pave the way towards realizing the ultimate goal of quantum transduction

Light-induced dynamic frequency shifting of microwave photons in a superconducting electro-optic converter

Hybrid superconducting-photonic microresonators are a promising platform for realizing microwave-to-optical transduction. However, the absorption of scattered photons by the superconductors leads to unintended microwave resonance frequency variation and linewidth broadening. Here, we experimentally study the dynamics of this effect and its impact on microwave-to-optics conversion in an integrated lithium niobate-superconductor hybrid resonator platform. We unveiled an adiabatic frequency shifting of the intracavity microwave photons induced by the fast photo-responses of the thin-film superconducting resonator. As a result, the temporal and spectral responses of electro-optics transduction are modified and well described by our theoretical model. This work provides important insights on the light-induced conversion dynamics which must be considered in future designs of hybrid superconducting-photonic system

Creating a capture zone in microfluidic flow greatly enhances the throughput and efficiency of cancer detection

Efficient capture of rare circulating tumor cells (CTCs) from blood samples is valuable for early cancer detection to improve the management of cancer. In this work, we developed a highly efficient microfluidics-based method for detecting CTCs in human blood. This is achieved by creating separate capture and flow zones in the microfluidic device (ZonesChip) and using patterned dielectrophoretic force to direct cells from the flow zone into the capture zone. This separation of the capture and flow zones minimizes the negative impact of high flow speed (and thus high throughput) and force in the flow zone on the capture efficiency, overcoming a major bottleneck of contemporary microfluidic approaches using overlapping flow and capture zones for CTC detection. When the flow speed is high (≥0.58 mm/s) in the flow zone, the separation of capture and flow zones in our ZonesChip could improve the capture efficiency from ∼0% (for conventional device without separating the two zones) to ∼100%. Our ZonesChip shows great promise as an effective platform for the detection of CTCs in blood from patients with early/localized-stage colorectal tumors

Trace amounts of polyâ βâ cyclodextrin wrapped carbon nanotubes for the microextraction of flavonoids in honey samples by capillary electrophoresis with lightâ emitting diode induced fluorescence detection

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122432/1/elps5830_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122432/2/elps5830.pd