Metal-organic chemical vapor deposition （MOCVD） grown ferromagnetic GaMnN films are investigated by photo- luminescence （PL） measurement with a mid-gap excitation wavelength of 405 nm. A sharp PL peak at 1.8 eV is...Metal-organic chemical vapor deposition （MOCVD） grown ferromagnetic GaMnN films are investigated by photo- luminescence （PL） measurement with a mid-gap excitation wavelength of 405 nm. A sharp PL peak at 1.8 eV is found and the PL intensity successively decreases with the addition of Mn, in which the Mn concentration of sample A is below 1% （[Mn]A =0.75%） but its PL intensity is stronger than other samples＇. The 1.8-eV PL peak is attributed to the recombination of electrons in the t2 state of the neutral Mn3＋ acceptor with holes in the valence band. With Mn concentration increasing, the intensity of the PL peak decreases and the magnetic increment reduces in our samples. The correlation between the PL peak intensity and ferromagnetism of the samples is discussed in combination with the experimental results.展开更多
We investigate the Ramsey fringes of a single electron spin of the nitrogen-vacancy center in diamond with different microwave radiation frequency detunings.The fast Fourier transform demonstrates that the Ramsey frin...We investigate the Ramsey fringes of a single electron spin of the nitrogen-vacancy center in diamond with different microwave radiation frequency detunings.The fast Fourier transform demonstrates that the Ramsey fringes consist of three components caused by hyperfine interaction with 14N nuclear spin,and the Ramsey fringes cannot be well explained without the phase term of the three components,which has not been mentioned before.Each phase is determined by the microwave frequency detuning and the resonant Rabi frequency as well as the π/2 pulse.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 10774078 and 60506013, the Program for New Century Excellent Talents in University （NCET-06-0213）, the SRF for ROCS （SEM）, the Startup Fund for New Employees of Nankai University, and the Marubun Research Promotion Foundation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61204008,11075176,and 60976090)the National Key Basic Research Special Foundation of China(Grant No.2013CB328705)
文摘Metal-organic chemical vapor deposition （MOCVD） grown ferromagnetic GaMnN films are investigated by photo- luminescence （PL） measurement with a mid-gap excitation wavelength of 405 nm. A sharp PL peak at 1.8 eV is found and the PL intensity successively decreases with the addition of Mn, in which the Mn concentration of sample A is below 1% （[Mn]A =0.75%） but its PL intensity is stronger than other samples＇. The 1.8-eV PL peak is attributed to the recombination of electrons in the t2 state of the neutral Mn3＋ acceptor with holes in the valence band. With Mn concentration increasing, the intensity of the PL peak decreases and the magnetic increment reduces in our samples. The correlation between the PL peak intensity and ferromagnetism of the samples is discussed in combination with the experimental results.
基金Supported by the National Basic Research Program of China under Grant No 2009CB929103the National Natural Science Foundation of China under Grant No 10974251.
文摘We investigate the Ramsey fringes of a single electron spin of the nitrogen-vacancy center in diamond with different microwave radiation frequency detunings.The fast Fourier transform demonstrates that the Ramsey fringes consist of three components caused by hyperfine interaction with 14N nuclear spin,and the Ramsey fringes cannot be well explained without the phase term of the three components,which has not been mentioned before.Each phase is determined by the microwave frequency detuning and the resonant Rabi frequency as well as the π/2 pulse.
