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Over the last decade, the development of Josephson devices based on van der Waals (vdW) materials has advanced rapidly, representing a paradigm shift driven by the advent of 2D materials. The diverse vdW materials library, combined with advanced fabrication techniques, enables the integration of materials with vastly disparate properties for scientific exploration. vdW Josephson junctions (JJs) offer a unique route to explore novel functionalities and associated physics that remain inaccessible in conventional JJs, which have reached an industrial level of fabrication. Beyond material diversity, vdW materials offer fundamental new control over device symmetries and enable the realization of Hamiltonians unique to 2D systems.After a broad introduction, I will discuss two classes of materials and devices. First, proximitized graphene-based Josephson junctions that are gate tunable. The graphene Josephson FET enables a quantum-noise-limited parametric amplifier with performance comparable to the best discrete amplifiers in this class [1]. One can realize extremely sensitive and fast bolometers [2] – useful for dark matter search, among other applications. Second, twisted van der Waals heterostructures based on the high-temperature superconductor Bi2Sr2CaCu2O8+δ enable the realization of a high-temperature Josephson diode [3] for the first time. Such Josephson diodes offer an opportunity to realize new devices at liquid nitrogen temperatures.While opportunities abound with vdW JJs, the challenge of scalability must be overcome to translate them into real-world devices.[1] "Quantum-noise-limited microwave amplification using a graphene Josephson junction" Joydip Sarkar et al. ,  Nature Nanotechnology 17, 1147 (2022).[2] “ Kerr non-linearity enhances the response of a graphene Josephson bolometer,” Sarkar et al. ,  Nature Communications volume 16, 7043 (2025).[3] "High-temperature Josephson diode," Sanat Ghosh et al. Nature Materials 23, 612 (2024).

The development of the infant gut microbiome is primarily influenced by delivery mode (vaginal or C-section) and the infant feeding type, with breast milk serving as the optimal source of nutrition. Breast milk contains human milk oligosaccharides (HMOs) that act as nourishment for the developing gut microbiome, potentially conferring advantages to specific bacterial species. Previous studies have demonstrated the ability of certain Bifidobacterium species to utilize individual HMOs, yet it is unclear whether the HMO composition impacts the gut bacteria community. In this seminar I will introduce the field of the gut microbiome and infant gut specifically, I will dig deeper into bacteria from the Bifidobacterium genus and their ability to utilize HMOs. From computational tool development to estimate their abundance, and our identification of a novel subspecies in the infant gut, to the experimental follow-ups of validation and examining the functional potential of the bacteria.  "No previous knowledge of the field is needed, just a critical and open mind."Students interested in meeting the speaker after the seminar may sign up here:LINKFOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.bio

I will mostly follow pages 73–97 in Terrence Tao’s book.

Being in the right place at the right time is essential for enzymes carrying out chemical reactions in cells. For example, enzymes that introduce S–S (disulfide) bonds during protein folding must operate in the intracellular compartment where their substrate proteins are synthesized (endoplasmic reticulum). One disulfide-introducing enzyme, Quiescin Sulfhydryl Oxidase 1 (QSOX1), drew our attention because it resides in a “wrong” location: a downstream compartment containing already folded proteins (Golgi apparatus). Setting out to understand why QSOX1 is found in an unusual place in cells, I discovered a previously unrecognized role for disulfide catalysis: in addition to assisting in protein folding, disulfides can also function as reversible molecular switches that regulate enzyme activity. I found that a family of sugar-adding enzymes (sialyltransferases), located in the same compartment as QSOX1, depend on local disulfide catalysis to remain active. This redox control mechanism is essential for maintaining the integrity of the intestinal mucosal layer, establishing QSOX1 as a key factor in promoting and preserving colon health.