9 papers
Robust Diamond Quantum Sensing in Double-Quantum 4-Ramsey Interferometry by Dual-Feedback Scheme
Yuta Araki, Takeharu Sekiguchi, Yuji Hatano +11
We developed a highly sensitive and long-term stable diamond quantum magnetometer by integrating a dual-feedback system that compensates for common- and differential-mode frequency…
Enhanced Emission and Two-Photon Interference of Lead-Vacancy Centers in Diamond Solid Immersion Lenses
Koyo Hirai, Eiki Ota, Yiyang Chen +8
A negatively charged lead-vacancy (PbV-) center in diamond is a novel quantum system which can be operated at a high temperature above 4 K owing to its large ground state splitting…
Coherent Dark State Formation of a Lead-Vacancy Spin Qubit in Diamond
Yiyang Chen, Koyo Hirai, Tzyy Zheng Neo +7
A lead-vacancy (PbV) center in diamond exhibits coherent emission above the liquid helium temperature, making it highly attractive for quantum network applications. Here, we report…
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…
A Highly Sensitive Diamond NV Magnetometer Using Ramsey Interferometry with a Short Sensor-to-Sample Distance
Yuta Araki, Takeharu Sekiguchi, Yuji Hatano +11
In this study, we developed a diamond quantum magnetometer based on Ramsey interferometry with a short sensor-to-sample distance. Conventional biomagnetic sensors with ensemble nit…
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.…
Multichannel highly sensitive diamond quantum magnetometer
Atsumi Yoshimura, Ayumi Kanamoto, Naota Sekiguchi +9
We demonstrate a highly sensitive real-time magnetometry method at two measurement points. This magnetometry method is based on the frequency-division multiplexing of continuous-wa…
Current comparator for both AC and DC ratio measurements with 10-8-level accuracy
Hidekazu Muramatsu, Yuta Kainuma, Hiromitsu Kato +11
Accurate measurements of alternating current (AC) and direct current(DC) ratios are fundamental to electric power metrology. However, conventional current comparators for AC and DC…