article published yes Y. Anahory author H. R. Naren author E. O. Lachman author S. Buhbut Sinai author A. Uri author L. Embon author E. Yaakobi author Y. Myasoedov author M. E. Huber author Rafal Klajn author 8e84690e-1e48-11ed-a02b-a1e6fb8bb53b E. Zeldov author Scanning nanoscale superconducting quantum interference devices (nanoSQUIDs) are of growing interest for highly sensitive quantitative imaging of magnetic, spintronic, and transport properties of low-dimensional systems. Utilizing specifically designed grooved quartz capillaries pulled into a sharp pipette, we have fabricated the smallest SQUID-on-tip (SOT) devices with effective diameters down to 39 nm. Integration of a resistive shunt in close proximity to the pipette apex combined with self-aligned deposition of In and Sn, have resulted in SOT with a flux noise of 42 n$\Phi_0$Hz$^{-1/2}$, yielding a record low spin noise of 0.29 $\mu_B$Hz$^{-1/2}$. In addition, the new SOTs function at sub-Kelvin temperatures and in high magnetic fields of over 2.5 T. Integrating the SOTs into a scanning probe microscope allowed us to image the stray field of a single Fe$_3$O$_4$ nanocube at 300 mK. Our results show that the easy magnetization axis direction undergoes a transition from the (111) direction at room temperature to an in-plane orientation, which could be attributed to the Verwey phase transition in Fe$_3$O$_4$. Royal Society of Chemistry2020 eng 2040-3372 2001.0334210.1039/C9NR08578E 1253174-3182 yes Anahory, Y., Naren, H. R., Lachman, E. O., Sinai, S. B., Uri, A., Embon, L., … Zeldov, E. (2020). SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging. <i>Nanoscale</i>. Royal Society of Chemistry. <a href="https://doi.org/10.1039/C9NR08578E">https://doi.org/10.1039/C9NR08578E</a> Anahory Y, Naren HR, Lachman EO, et al. SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging. <i>Nanoscale</i>. 2020;12(5):3174-3182. doi:<a href="https://doi.org/10.1039/C9NR08578E">10.1039/C9NR08578E</a> Y. Anahory, H.R. Naren, E.O. Lachman, S.B. Sinai, A. Uri, L. Embon, E. Yaakobi, Y. Myasoedov, M.E. Huber, R. Klajn, E. Zeldov, Nanoscale 12 (2020) 3174–3182. Anahory, Y., H. R. Naren, E. O. Lachman, S. Buhbut Sinai, A. Uri, L. Embon, E. Yaakobi, et al. “SQUID-on-Tip with Single-Electron Spin Sensitivity for High-Field and Ultra-Low Temperature Nanomagnetic Imaging.” <i>Nanoscale</i>. Royal Society of Chemistry, 2020. <a href="https://doi.org/10.1039/C9NR08578E">https://doi.org/10.1039/C9NR08578E</a>. Y. Anahory <i>et al.</i>, “SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging,” <i>Nanoscale</i>, vol. 12, no. 5. Royal Society of Chemistry, pp. 3174–3182, 2020. Anahory Y, Naren HR, Lachman EO, Sinai SB, Uri A, Embon L, Yaakobi E, Myasoedov Y, Huber ME, Klajn R, Zeldov E. 2020. SQUID-on-tip with single-electron spin sensitivity for high-field and ultra-low temperature nanomagnetic imaging. Nanoscale. 12(5), 3174–3182. Anahory, Y., et al. “SQUID-on-Tip with Single-Electron Spin Sensitivity for High-Field and Ultra-Low Temperature Nanomagnetic Imaging.” <i>Nanoscale</i>, vol. 12, no. 5, Royal Society of Chemistry, 2020, pp. 3174–82, doi:<a href="https://doi.org/10.1039/C9NR08578E">10.1039/C9NR08578E</a>. 133412023-08-01T08:27:12Z2023-08-02T09:35:52Z