Biyolojik sistemler için kuantum metroloji

This thesis outlines three main projects which link biology, quantum information, and metrology. It culminates with future perspectives on quantum biology and various research related to the brain. The first project begins with an examination of quantum information, moving from theoretical concepts to their practical implementation in biological environments. It tackles the issue of maintaining quantum coherence and entanglement despite the presence of environmental noise in open quantum systems. Geometrical optimization using buffer spins as a protective network of the quantum information in the central spin is introduced. Furthermore, the phenomenon of entanglement in a corresponding biological context is investigated by carrying out preliminary analysis of a more realistic system, the Posner cluster. In the second project, the focus shifts to quantum sensing, with particular attention to the Nitrogen-Vacancy (NV) center, a point defect in diamond. The role of NV centers as sensitive probes is examined in biological contexts, particularly for detecting magnetic fields. The application of spin squeezing to NV centers, when considered as qutrit (three-level) systems, may potentially improve the precision of magnetic field measurements. This precision is quantified using Quantum Fisher Information. Moreover, the integration of a selective bioresponsive material, such as hydrogel, that act as a transducer in the measurement setup could open new avenues to a wider range of biological measurements. The third project explores the use of quantum light to probe biological systems. It examines how quantum mechanics, particularly multipartite photon entanglement, can enhance our understanding of vision. This is achieved through simulations of psychophysical experiments, utilizing entanglement witnesses, a class of observables used to detect entanglement. Starting with bipartite entangled state, and then, generalizing to tripartite case, the probability of seeing of the human eye is determined for a certain range of additive noise levels and visual thresholds. The results shed light on the human eye's capacity to witness entanglement. The three topics covered demonstrate the intertwining relationship between biology and quantum physics. This is further detailed as future perspectives of research by posing some of the most intriguing and fundamental questions of all time in science. A special emphasis of the connection of this relationship to the brain is laid. Eventually, building on such endeavors will become the groundwork of significant potential contributions to future developments in biological and medical sciences.