_NV centers_ (Nitrogen-Vacancy centers) are tiny defects in diamond crystals that have become powerful tools in quantum technology. These defects occur when a nitrogen atom takes the place of a carbon atom in the diamond lattice, leaving a neighboring spot vacant. Remarkably, this simple imperfection gives rise to unique quantum properties that are useful for a variety of applications. One of the most fascinating features of NV centers is that they can be manipulated and read out using [[Light|light]] and [[Magnetic Field|magnetic fields]]. When illuminated with a [[Laser|laser]], NV centers emit fluorescent light, and the brightness of this light depends on their quantum state. This property allows scientists to detect and control the state of the NV center, even at room temperature. ![[nv_center.excalidraw.light.svg]] NV centers are particularly valuable in the field of [[Quantum Metrology|quantum metrology]]. They are highly sensitive to magnetic and [[Electric Field|electric fields]], temperature changes, and even pressure variations. This makes them ideal for applications like [[Length Scales|nanoscale]] magnetometry, where they can detect extremely small magnetic fields with high spatial resolution. For example, NV centers are used to map magnetic fields in biological samples, providing insights into neuron activity and other cellular processes. Moreover, NV centers are being explored for quantum [[Quantum Communication|communication]] and [[Quantum Computer|computing]]. Their long [[Coherence Time|coherence times]] allow them to store [[Quantum Information|quantum information]] for relatively long periods, making them potential candidates for [[Qubit|qubits]]. Researchers are also investigating how NV centers can be [[Entanglement|entangled]] and used for secure quantum communication networks. In fact, the first loophole-free [[Bell Inequality|Bell inequality]] violation has been reported using a [[Photon|photonic]] link to entangle the [[Electron|electron]] [[Spin|spins]] of two NV centers. >[!read]- Further Reading >- [[Laser]] >- [[Platform - Quantum Dots]] >- [[Quantum Metrology]] >- [[Qubit]] >[!ref]- References >- B. Hensen, H. Bernien, A. E. Dréau, A. Reiserer, N. Kalb, M. S. Blok, J. Ruitenberg, R. F. L. Vermeulen, R. N. Schouten, C. Abellán, W. Amaya, V. Pruneri, M. W. Mitchell, M. Markham, D. J. Twitchen, D. Elkouss, S. Wehner, T. H. Taminiau, and R. Hanson, Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometers, Nature **526**, 682 (2015).