Room-temperature coherent coupling of single spins in diamond (original) (raw)
Related papers
Single-Qubit Operations with the Nitrogen-Vacancy Center in Diamond
physica status solidi (b), 2002
A concept combining optics and microwave pulses with the negative charge-state of the nitrogenvacancy (NV-) center in diamond is demonstrated through experiments that are equivalent to single-qubit gates, and decoherence for this qubit is examined. The spin levels of the ground state provide the two-level system. Optical excitation provides polarization of these states. The polarized state is operated coherently by 35 GHz microwave pulses. The final state is read out through the photoluminescence intensity. Decoherence arises from different sources for different samples. For high-pressure, high-temperature synthetic diamonds, the high concentration of substitutional N limits the phase-memory to a few ms. In a single-crystal CVD diamond, the phase memory time is at least 32 ms at 100 K. 14 N is tightly coupled to the electronic spin and produces modulation of the electron-spin echo decay under certain conditions. A two-qubit gate is proposed using this nuclear spin. This demonstration provides a great deal of insight into quantum devices in the solid state with some possibility for real application.
Measurements of spin-coherence in NV centers for diamond-based quantum sensors
2021 SBFoton International Optics and Photonics Conference (SBFoton IOPC)
One of the biggest challenges to implement quantum protocols and quantum information processing (QIP) is achieving long coherence times, usually requiring systems at ultra-low temperatures. The nitrogen-vacancy (NV) center in diamond is a promising alternative to this problem. Due to its spin properties, easy manipulation, and the possibility of doing optical state initialization and readout, it quickly became one of the best solid-state spin systems for QIP at room temperature. Here*, we present the characterization of the spin-coherence of an ensemble of NV centers in an engineered sample of ultrapure diamond as a testbed for quantum protocols for quantum metrology.
Excited-state spin coherence of a single nitrogen-vacancy centre in diamond
Nature Physics, 2010
Nitrogen-vacancy centres in diamond are a solid-state analogue of trapped atoms, with fine structure in both the ground and excited states that may be used for advanced quantum control. These centres are promising candidates for spin-based quantum information processing 1-3 and magnetometry 4-6 at room temperature. Knowledge of the excited-state (ES) structure and coherence is critical to evaluating the ES as a room-temperature quantum resource, for example for a fast, optically gated swap operation with a nuclear-spin memory 7 . Here we report experiments that probe the ES-spin coherence of single nitrogen-vacancy centres. Using a combination of pulsed-laser excitation and nanosecond-scale microwave manipulation, we observed ES Rabi oscillations, and multipulse resonant control enabled us to study coherent ES electron/nuclear-spin interactions. To understand these processes, we developed a finite-temperature theory of ES spin dynamics that also provides a pathway towards engineering longer ES spin coherence.
Cavity enhanced spin measurement of the ground state spin of an NV center in diamond
A key step in the use of diamond nitrogen vacancy (NV) centers for quantum computational tasks is a single shot quantum non-demolition measurement of the electronic spin state. Here, we propose a high fidelity measurement of the ground state spin of a single NV center, using the effects of cavity quantum electrodynamics. The scheme we propose is based in the one-dimensional atom or Purcell regime, removing the need for high Q cavities that are challenging to fabricate. The ground state spin of the NV center has a splitting of ≈6-10 µeV, which can be resolved in a high-resolution absorption measurement. By incorporating the center in a low-Q and low volume cavity we show that it is possible to perform single shot readout of the ground state spin using a weak laser with an error rate of ≈7 × 10 −3 , when realistic experimental parameters are considered. Since very low levels of light are used to probe the state of the spin we limit the number of florescence cycles, which dramatically reduces the measurement induced decoherence approximating a non-demolition measurement of ground state spin.
Electron spin decoherence of single nitrogen-vacancy defects in diamond
2008
Isolated spins in solid-state systems are currently being explored as candidates for good quantum bits, with applications ranging from quantum computation 1–3 and quantum communication 4 to magnetic sensing. 5–7 The nitrogenvacancy NV center in diamond is one such isolated spin system. It can be prepared and detected using optical fields, and microwave radiation can be used to rotate the spin.
Using spins in diamond for quantum technologies
Delft University of Technolgoy, 2023
Solid-state defect centers, such as the nitrogen-vacancy centers in diamond, represent a promising and versatile platform for quantum technologies. This thesis focuses on overcoming the challenge of noise in diamond to facilitate its practical use in various quantum technology applications.
Physical Review B, 2001
Electron spin echoes were performed on nitrogen-vacancy (N-V) centers in diamond using optical polarization and detection and 35 GHz microwave control. The experiments demonstrate an approach to quantum information in the solid state. A phase memory time of 3.6 s was measured, and coupling of the electronic spin to the 14 N nuclear spin was observed. Because of the favorable properties of the N-V center, interesting extensions of these single-qubit operations can be proposed.
In this article we investigate the dynamics of a single negatively charged nitrogen-vacancy center (NV − ) coupled to the spin of the nucleus of a 15-nitrogen atom and show that high fidelity gate operations are possible without the need for complicated composite pulse sequences. These operations include both the electron and nuclear spin rotations, as well as an entangling gate between them. These are experimentally realizable gates with current technology of sufficiently high fidelities that they can be used to build graph states for quantum information processing tasks.
Hands-on quantum sensing with NV centers in diamond
Hands-on quantum sensing with NV centers in diamond, 2023
The physical properties of diamond crystals, such as color or electrical conductivity, can be controlled via impurities. In particular, when doped with nitrogen and under certain conditions, optically active nitrogen-vacany centers (N V) can be induced. The center is an outstanding quantum spin system that enables, under ambient conditions, optical initialization, readout, and coherent microwave control with applications in sensing and quantum information. Under optical and radio frequency excitation, the Zeeman splitting of the degenerate states allows the quantitative measurement of external magnetic fields with high sensitivity. This study provides a pedagogical introduction to the properties of the N V centers as well as a step-by-step process to develop and test, a simple magnetic quantum sensor based on color centers with large potential for the development of highly compact multi-sensor systems.