CMP Journal 2025-01-21
Statistics
Nature Nanotechnology: 1
Nature Physics: 1
Nature Nanotechnology
ON-OFF nanopores for optical control of transmembrane ionic communication
Original Paper | Nanopores | 2025-01-20 19:00 EST
Xingzao Wang, Aidan Kerckhoffs, Jorin Riexinger, Matthew Cornall, Matthew J. Langton, Hagan Bayley, Yujia Qing
Nanoscale photoswitchable proteins could facilitate precise spatiotemporal control of transmembrane communication and support studies in synthetic biology, neuroscience and bioelectronics. Here, through covalent modification of the α-haemolysin protein pore with arylazopyrazole photoswitches, we produced ‘photopores' that transition between iontronic resistor and diode modes in response to irradiation at orthogonal wavelengths. In the diode mode, a low-leak OFF-state nanopore exhibits a reversible increase in unitary conductance of more than 20-fold upon irradiation at 365 nm. A rectification ratio of >5 was achieved with photopores in the diode state by either direct or alternating voltage input. Unlike conventional electronic phototransistors with intensity-dependent photoelectric responses, the photopores regulated current output solely based on the wavelength(s) of monochromatic or dual-wavelength irradiation. Dual-wavelength irradiation at various relative intensities allowed graded adjustment of the photopore conductance. By using these properties, photonic signals encoding text or graphic messages were converted into ionic signals, highlighting the potential applications of photopores as components of smart devices in synthetic biology.
Nanopores, Photochemistry
Nature Physics
Floquet-Bloch manipulation of the Dirac gap in a topological antiferromagnet
Original Paper | Electronic properties and materials | 2025-01-20 19:00 EST
Nina Bielinski, Rajas Chari, Julian May-Mann, Soyeun Kim, Jack Zwettler, Yujun Deng, Anuva Aishwarya, Subhajit Roychowdhury, Chandra Shekhar, Makoto Hashimoto, Donghui Lu, Jiaqiang Yan, Claudia Felser, Vidya Madhavan, Zhi-Xun Shen, Taylor L. Hughes, Fahad Mahmood
Floquet-Bloch manipulation, achieved by driving a material periodically with a laser pulse, is a method that enables the engineering of electronic and magnetic phases in solids by effectively modifying the structure of their electronic bands. However, the application of Floquet-Bloch manipulation in topological magnetic systems, particularly those with inherent disorder, remains largely unexplored. Here we realize Floquet-Bloch manipulation of the Dirac surface-state mass of the topological antiferromagnet MnBi2Te4. Using time- and angle-resolved photoemission spectroscopy, we show that opposite helicities of mid-infrared circularly polarized light result in substantially different Dirac mass gaps in the antiferromagnetic phase, despite the equilibrium Dirac cone being massless. We explain our findings in terms of a Dirac fermion with a random mass. Our results underscore Floquet-Bloch manipulation as a powerful tool for controlling topology, even in the presence of disorder, and for uncovering properties of materials that may elude conventional probes.
Electronic properties and materials, Topological insulators