44 citations · 250 across the 29 of their papers we have counts for
30 papers
Efficient creation of shallow NV ensembles by high-angle ion implantation
Kento Sasaki, Hideyuki Watanabe, Tokuyuki Teraji +3
Negatively charged nitrogen-vacancy (NV) centers located a few nanometers below the diamond surface are key quantum defects for nanoscale sensing of external spins. However, th…
Engineering Nanodiamonds for Quantum Sensing: Material Constraints at the Nanoscale
Ashutosh Rathi, Keisuke Oshimi, Kento Sasaki +6
Optically addressable solid-state spin defects have emerged as powerful multimodal quantum sensors, with nitrogen-vacancy (NV) centers in bulk diamond providing benchmark quantum c…
High-pressure magnetic transition in iron observed via diamond quantum sensing
Kouki Yamamoto, Kenshin Uriu, Ryotaro Suda +5
Diamond quantum sensors offer high precision and spatial resolution as magnetic probes, making them promising for a wide range of applications. While diamond anvil cells (DACs) can…
Spin-coherence characterization of boron vacancy defects in hexagonal boron nitride with broadband microwave pulses
Yuki Nakamura, Takuya Iwasaki, Shu Nakaharai +6
Negatively charged boron vacancy (VB-) defects in hexagonal boron nitride (hBN) are promising for nanoscale-proximity quantum sensing. To evaluate their performance, it is importan…
Wide-field magnetic imaging of shielding-current-driven vortex rearrangement under local heating using diamond quantum sensors
Ryoei Ota, Shunsuke Nishimura, Koki Honda +6
Understanding and controlling vortex motion in superconductors are important both for suppressing dissipation in superconducting devices and for device applications that exploit vo…
Observation of individual vortex penetration in a coplanar superconducting resonator
Kirill Shulga, Shunsuke Nishimura, Pavel A. Volkov +7
We demonstrate the microwave signatures of individual Abrikosov-vortex penetration events in superconducting microwave resonators. resonators with a narrowed region near the…
Visualization of Current-Driven Vortex Formation in High- Cuprate Superconductors
Shunsuke Nishimura, Takeyuki Tsuji, Takayuki Iwasaki +3
Type-II superconductors exhibit hysteretic behavior due to the presence of quantum vortices, and the order in which temperature and external field are varied plays a decisive role.…
Beyond ensemble averaging: Parallelized single-shot readout of hole capture in diamond
Richard Monge, Yuki Nakamura, Olaf Bach +7
Understanding the generation, transport and capture of charge carriers in semiconductors is of fundamental technological importance. However, the ensemble measurement techniques ub…
GPa Pressure Imaging Using Nanodiamond Quantum Sensors
Ryotaro Suda, Kenshin Uriu, Kouki Yamamoto +5
We demonstrate wide-field optical microscopy of the pressure distribution at approximately 20 GPa in a diamond anvil cell (DAC), using nitrogen-vacancy (NV) centers in nanodiamonds…
Nanodiamond quantum thermometry assisted with machine learning
Kouki Yamamoto, Kensuke Ogawa, Moeta Tsukamoto +3
Nanodiamonds (NDs) are quantum sensors that enable local temperature measurements, taking advantage of their small size. Though the model based analysis methods have been used for…
Quantitative imaging of nonlinear spin-wave propagation using diamond quantum sensors
Kensuke Ogawa, Moeta Tsukamoto, Yusuke Mori +7
Spin waves propagating in magnetic materials exhibit nonlinear behavior at large amplitudes due to the competition between excitation and relaxation, providing an attractive platfo…
Systematic investigation of dynamic nuclear polarization with boron vacancy in hexagonal boron nitride
Yuki Nakamura, Shunsuke Nishimura, Takuya Iwasaki +7
Dynamic nuclear polarization (DNP) using the boron vacancy () in hexagonal boron nitride (hBN) has gained increasing attention. Understanding this DNP requires syst…
Wideband wide-field imaging of spin-wave propagation using diamond quantum sensors
Kensuke Ogawa, Moeta Tsukamoto, Yusuke Mori +6
Imaging spin-wave propagation in magnetic materials in a wide frequency range is crucial for understanding and applying spin-wave dynamics. Recently, nitrogen-vacancy (NV) centers…
Systematic characterization of nanoscale -BN quantum sensor spots created by helium-ion microscopy
Hao Gu, Moeta Tsukamoto, Yuki Nakamura +8
The nanosized boron vacancy () defect spot in hexagonal boron nitride (-BN) is promising for a local magnetic field quantum sensor. One of its advantages is that…
Observation of chiral domain walls in an octupole-ordered antiferromagnet
Moeta Tsukamoto, Zhewen Xu, Tomoya Higo +10
Spin chirality in antiferromagnets offers new opportunities for spintronics. The kagome antiferromagnet Mn3Sn is a paradigmatic material in which the antiferromagnetic order parame…
Investigations of optical aberration on quantum diamond microscopy toward high spatial resolution and sensitivity
Shunsuke Nishimura, Moeta Tsukamoto, Kento Sasaki +1
Quantum diamond microscopy (QDM), which employs nitrogen-vacancy (NV) center ensembles, is a promising approach to quantitatively imaging magnetic fields with both high resolution…
Demonstration of highly-sensitive wideband microwave sensing using ensemble nitrogen-vacancy centers
Kensuke Ogawa, Shunsuke Nishimura, Kento Sasaki +1
Microwave magnetometry is essential for the advancement of microwave technologies. We demonstrate a broadband microwave sensing protocol using the AC Zeeman effect with ensemble ni…
Suppression of Pulsed Dynamic Nuclear Polarization by Many-Body Spin Dynamics
Kento Sasaki, Eisuke Abe
We study a mechanism by which nuclear hyperpolarization due to the polarization transfer from a microwave-pulse-controlled electron spin is suppressed. From analytical and numerica…
Optical-power-dependent splitting of magnetic resonance in nitrogen-vacancy centers in diamond
Shuji Ito, Moeta Tsukamoto, Kensuke Ogawa +3
Nitrogen-vacancy (NV) centers in diamonds are a powerful tool for accurate magnetic field measurements. The key is precisely estimating the field-dependent splitting width of the o…
Nitrogen isotope effects on boron vacancy quantum sensors in hexagonal boron nitride
Kento Sasaki, Takashi Taniguchi, Kensuke Kobayashi
There has been growing interest in studying hexagonal boron nitride (hBN) for quantum technologies. Here, we investigate nitrogen isotope effects on boron vacancy (V) de…
Demonstration of geometric diabatic control of quantum states
Kento Sasaki, Yuki Nakamura, Tokuyuki Teraji +2
Geometric effects can play a pivotal role in streamlining quantum manipulation. We demonstrate a geometric diabatic control, that is, perfect tunneling between spin states in a dia…
Frequency-tunable magnetic field sensing using continuous-wave optically detected magnetic resonance with nitrogen-vacancy centers in diamond
Ryusei Okaniwa, Takumi Mikawa, Yuichiro Matsuzaki +8
The nitrogen-vacancy (NV) center is a promising candidate to realize practical quantum sensors with high sensitivity and high spatial resolution, even at room temperature and atmos…
Wide-field quantitative magnetic imaging of superconducting vortices using perfectly aligned quantum sensors
Shunsuke Nishimura, Taku Kobayashi, Daichi Sasaki +5
Various techniques have been applied to visualize superconducting vortices, providing clues to their electromagnetic response. Here, we present a wide-field, quantitative imaging o…
Magnetic field imaging by hBN quantum sensor nanoarray
Kento Sasaki, Yuki Nakamura, Hao Gu +8
Placing a sensor close to the target at the nano-level is a central challenge in quantum sensing. We demonstrate high-spatial-resolution magnetic field imaging with a boron vacancy…