INTRASPECIES PTEROMYS-TALLENNUSTEN (SCIURIDAE, MAMMALIA) TALVEN TURKIVÄRJEN VÄRITTÄMINEN MALLISSA

Peer reviewe

Kramers Degenerated Spin Systems "NV Center + Few Proximal 13C Nuclei" in Diamond for Single-Spin Magnetometry

Spin systems consisted of single electronic spin S=1 of the NV center and few nearby carbon-13 nuclei spins I=1/2 in diamond lattice which can be used as a small register of a quantum computer or as a sensor of a magnetic field are studied both numerically and analytically using spin Hamiltonian method. At odd number of carbon-13 nuclei the eigenstates of the spin system at zero external magnetic field are twofold degenerated (Kramers degeneration) due to time reversal invariance of the spin Hamiltonian. This degeneracy is lifted only by external magnetic field regardless of the presence of any electric (crystal) field which also lifts the degeneracy thus hindering measurement of external magnetic field. Therefore the Kramers-degenerated spin systems are especially perspective for measurement of a local magnetic field by the NV-based single-spin quantum magnetometer. Here we discussed spin properties of such spin systems using the parameters of hyperfine NV-13C interactions taken from electron paramagnetic resonance EPR experiments on NV ensemble or from optically detected magnetic resonance (ODMR) experiments on single NV centers as well as from ab initio (Density Functional Theory (DFT)) simulation of H-terminated carbon clusters hosting NV centers. Moreover, we calculated by DFT the zero-field splitting parameters D and E for the NV center. For the simplest spin system "NV+single carbon-13" we got simple approximate analytical expressions for energy levels and eigenstates

Kramers Degenerated Spin Systems "NV Center + Few Proximal 13C Nuclei" in Diamond for Single-Spin Magnetometry

Spin systems consisted of single electronic spin S=1 of the NV center and few nearby carbon-13 nuclei spins I=1/2 in diamond lattice which can be used as a small register of a quantum computer or as a sensor of a magnetic field are studied both numerically and analytically using spin Hamiltonian method. At odd number of carbon-13 nuclei the eigenstates of the spin system at zero external magnetic field are twofold degenerated (Kramers degeneration) due to time reversal invariance of the spin Hamiltonian. This degeneracy is lifted only by external magnetic field regardless of the presence of any electric (crystal) field which also lifts the degeneracy thus hindering measurement of external magnetic field. Therefore the Kramers-degenerated spin systems are especially perspective for measurement of a local magnetic field by the NV-based single-spin quantum magnetometer. Here we discussed spin properties of such spin systems using the parameters of hyperfine NV-13C interactions taken from electron paramagnetic resonance EPR experiments on NV ensemble or from optically detected magnetic resonance (ODMR) experiments on single NV centers as well as from ab initio (Density Functional Theory (DFT)) simulation of H-terminated carbon clusters hosting NV centers. Moreover, we calculated by DFT the zero-field splitting parameters D and E for the NV center. For the simplest spin system "NV+single carbon-13" we got simple approximate analytical expressions for energy levels and eigenstates

Hyperfine Interactions in the NV-13C Quantum Registers in Diamond Grown from the Azaadamantane Seed

Nanostructured diamonds hosting optically active paramagnetic color centers (NV, SiV, GeV, etc.) and hyperfine-coupled with them quantum memory 13C nuclear spins situated in diamond lattice are currently of great interest to implement emerging quantum technologies (quantum information processing, quantum sensing and metrology). Current methods of creation such as electronic-nuclear spin systems are inherently probabilistic with respect to mutual location of color center electronic spin and 13C nuclear spins. A new bottom-up approach to fabricate such systems is to synthesize first chemically appropriate diamond-like organic molecules containing desired isotopic constituents in definite positions and then use them as a seed for diamond growth to produce macroscopic diamonds, subsequently creating vacancy-related color centers in them. In particular, diamonds incorporating coupled NV-13C spin systems (quantum registers) with specific mutual arrangements of NV and 13C can be obtained from anisotopic azaadamantane molecule. Here we predict the characteristics of hyperfine interactions (hfi) for the NV-13C systems in diamonds grown from various isotopically substituted azaadamantane molecules differing in 13C position in the seed, as well as the orientation of the NV center in the post-obtained diamond. We used the spatial and hfi data simulated earlier for the H-terminated cluster C510[NV]-H252. The data obtained can be used to identify (and correlate with the seed used) the specific NV-13C spin system by measuring, e.g., the hfi-induced splitting of the mS = ±1 sublevels of the NV center in optically detected magnetic resonance (ODMR) spectra being characteristic for various NV-13C systems