Control of all the transitions between ground state manifolds of nitrogen vacancy centers in diamonds by applying external magnetic driving fields
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2020-10-21 |
| Journal | Japanese Journal of Applied Physics |
| Authors | Tatsuma Yamaguchi, Yuichiro Matsuzaki, Soya Saijo, Hideyuki Watanabe, Norikazu Mizuochi |
| Institutions | National Institute of Advanced Industrial Science and Technology, Keio University |
| Citations | 5 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis research demonstrates a simplified, robust method for achieving full quantum control over the ground state manifold of Nitrogen Vacancy (NV) centers in diamond, a critical step for advanced quantum technologies.
- Core Achievement: Demonstrated coherent control (Rabi oscillations) of all three transitions (|0> to |B>, |0> to |D>, and |B> to |D>) within the NV center ground state sublevels.
- Key Innovation: The application of a DC magnetic field orthogonal (perpendicular) to the NV axis. This configuration defines new energy eigenstates (|0>, |B>, |D>) that are all magnetically coupled, allowing the use of AC magnetic fields (MW and RF) for full control.
- Practical Advantage: The scheme operates at room temperature and atmospheric pressure and is significantly simpler than previous methods, which required complex fabrication involving mechanical vibrations or electric field application.
- Driving Fields: Microwave (MW) pulses control the two high-frequency transitions (|0> to |B> and |0> to |D>), while Radio Frequency (RF) pulses control the low-frequency transition (|B> to |D>).
- Performance Metric: Demonstrated a pi rotation pulse duration of approximately 210 ns for the MW-driven transitions.
- Impact: Paves the way for exploiting the full potential of the spin-1 NV system for high-sensitivity quantum sensing and quantum information processing (QIP).
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Quantum System | Nitrogen Vacancy (NV) Center | N/A | Spin-1 ground state manifold in diamond. |
| Operating Condition | Room Temperature | N/A | Enables practical, ambient-condition applications. |
| DC Magnetic Field | Weak, Orthogonal | N/A | Applied perpendicular to the NV axis to lift degeneracy and define eigenstates ( |
| Transition 1 Frequency | 2.8768 | GHz | Resonance frequency between |
| Transition 2 Frequency | 2.8847 | GHz | Resonance frequency between |
| Transition 3 Frequency | ~7.9 | MHz | Resonance frequency between |
| Pi Pulse Duration (MW) | ~210 | ns | Time required for pi rotation between |
| Hamiltonian Condition | D >> g”bBx >> Ey | N/A | Condition used for simplifying the NV Hamiltonian under orthogonal field. |
| Control Method | External Magnetic Driving Fields | N/A | Uses MW and RF pulses; avoids mechanical or electric field complexity. |
Key Methodologies
Section titled âKey MethodologiesâThe experiment utilized Optically Detected Magnetic Resonance (ODMR) under continuous-wave and pulsed magnetic driving fields at room temperature.
- Sample and Setup: An ensemble of NV centers in diamond was used, employing the same physical setup as previous work (Ref. [34]).
- DC Magnetic Field Application: A weak DC magnetic field was applied orthogonal (perpendicular) to one of the four possible NV crystallographic axes. This field lifts the degeneracy, allowing frequency selectivity to address only the NV centers aligned perpendicular to the field.
- Initialization: The NV centers were initialized into the |0> state using a green laser pulse.
- MW Pulse Control: Microwave pulses were applied to drive the two high-frequency transitions:
- |0> to |B> (Resonance frequency: 2.8768 GHz).
- |0> to |D> (Resonance frequency: 2.8847 GHz).
- Rabi oscillations were observed by sweeping the MW pulse duration.
- RF Pulse Control: Radio Frequency pulses were applied to drive the low-frequency transition:
- |B> to |D> (Resonance frequency: ~7.9 MHz).
- Rabi oscillations were investigated by sweeping the RF pulse duration, frequency, and intensity.
- Readout Sequence (for |B> to |D> transition): Due to similar photoluminescence (PL) from |B> and |D>, a complex sequence was required to read the state of |B>:
- Initialize to |0>.
- Apply MW Ï pulse (|0> to |B>).
- Apply RF pulse (sweep duration, driving |B> to |D>).
- Apply MW Ï pulse (converts remaining |B> population back to |0>).
- Apply Laser pulse for final PL readout (detecting the population in |0>).
- Verification: Experimental Rabi oscillation results were compared against theoretical calculations based on the simplified Hamiltonian, showing good agreement.
Commercial Applications
Section titled âCommercial ApplicationsâThe ability to fully control the three ground state sublevels of NV centers significantly enhances their utility across various quantum technologies:
- Quantum Sensing:
- High-sensitivity magnetic field sensing (AC and DC).
- High-sensitivity temperature sensing.
- Electric field sensing.
- The use of all three levels (the Î-system) enables novel sensing schemes that do not require complex pulse control.
- Quantum Information Processing (QIP):
- Realization of quantum gates and computation using the three-level (qutrit) system, potentially increasing information density compared to standard two-level qubits.
- Quantum Memory:
- Utilizing the NV center as a robust quantum memory element, particularly for coupling with superconducting qubits (as demonstrated in related work).
- Quantum Communication:
- Facilitating coherent coupling between NV centers and optical photons for long-distance quantum networking.
- Quantum Simulation:
- Realizing quantum simulators based on spin-spin coupling within the diamond lattice.
View Original Abstract
Abstract We demonstrate control of all the three transitions among the ground state sublevels of NV centers by applying magnetic driving fields. To address the states of a specific NV axis among the four axes, we apply a magnetic field orthogonal to the NV axis. We control two transitions by microwave pulses and the remaining transition by radio frequency (RF) pulses. In particular, we investigate the dependence of Rabi oscillations on the frequency and intensity of the RF pulses. In addition, we perform a Ï pulse by the RF pulses and measured the coherence time between the ground state sublevels. Our results pave the way for control of NV centers for the realization of quantum information processing and quantum sensing.