We have developed a versatile near-field microscopy platform that can operate at high magnetic fields and below liquid-helium temperatures. We use this platform to demonstrate an extreme terahertz (THz) nanoscope operation and to obtain the first cryogenic magneto-THz time-domain nano-spectroscopy/imaging at temperatures as low as 1.8 K, magnetic fields of up to 5 T, and with operation of 0-2 THz. Our Cryogenic Magneto-Terahertz Scattering-type Scanning Near-field Optical Microscope (or cm-THz-sSNOM) instrument is comprised of three main equipment: (i) a 5 T split pair magnetic cryostat with a custom made insert, (ii) a custom sSNOM instrument capable of accepting ultrafast THz excitation, and (iii) a MHz repetition rate, femtosecond laser amplifier for broadband THz pulse generation and sensitive detection. We apply the cm-THz-sSNOM to obtain proof of principle measurements of superconductors and topological semimetals. The new capabilities demonstrated break grounds for studying quantum materials that require an extreme environment of cryogenic operation and/or applied magnetic fields in nanometer space, femtosecond time, and THz energy scales.
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http://dx.doi.org/10.1063/5.0130680 | DOI Listing |
J Am Chem Soc
January 2025
Institute for Materials Chemistry and Engineering and IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
Switching electric polarization by external stimuli constitutes a technical foundation for various applications. Here, we reported the observation of polarization-switching behavior in an oxo-bridged mixed-valence complex [FeO(piv)(py)] (piv = pivalate, py = pyridine). Detailed variable-temperature Mössbauer spectral analyses unambiguously confirm the occurrence of an electron localization-delocalization transition between two inequivalent Fe sites.
View Article and Find Full Text PDFNMR Biomed
March 2025
Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands.
Deuterium (H) and phosphorus (P) magnetic resonance spectroscopy (MRS) are complementary methods for evaluating tissue metabolism noninvasively in vivo. Combined H and P MRS would therefore be of interest for various applications, from cancer to diabetes. Loop coils are commonly used in X-nuclei studies in the human body for both transmit and receive.
View Article and Find Full Text PDFJ Magn Reson Imaging
January 2025
Department of Optical and Biophysical Systems, Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic.
Substantial research over the past two decades has established that magnetic fields affect fundamental cellular processes, including gene expression. However, since biological cells and subcellular components exhibit diamagnetic behavior and are therefore subjected to very small magnetic forces that cannot directly compete with the viscoelastic and bioelectric intracellular forces responsible for cellular machinery functions, it becomes challenging to understand cell-magnetic field interactions and to reveal the mechanisms through which these interactions differentially influence gene expression in cells. The limited understanding of the molecular mechanisms underlying biomagnetic effects has hindered progress in developing effective therapeutic applications of magnetic fields.
View Article and Find Full Text PDFJ Exp Biol
February 2025
Ornithology Lab, Zoological Institute of the Russian Academy of Sciences, 199034 St Petersburg, Russia.
Every year, billions of birds migrate to optimize their foraging, shelter and breeding. They use an inclination compass, which, unlike the technical compass, distinguishes between the directions towards the magnetic equator from the magnetic pole based on magnetic inclination angles, which range from ±90 deg at the poles to 0 deg at the equator. During autumn migration, some species cross the magnetic equator, where field lines are horizontal, i.
View Article and Find Full Text PDFCurr Pharm Des
January 2025
Department of Pharmaceutics, College of Pharmacy, Shaqra University, Shaqra 11961, Kingdom of Saudi Arabia.
Nanogels (NGs) are presently the focus of extensive research because of their special qualities, including minimal particle size, excellent encapsulating efficacy, and minimizing the breakdown of active compounds. As a result, NGs are great candidates for drug delivery systems. Cross-linked nanoparticles (NPs) called stimulus-responsive NGs are comprised of synthetic, natural, or a combination of natural and synthetic polymers.
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