135 research outputs found
Electrical Detection of Coherent Nuclear Spin Oscillations in Phosphorus-Doped Silicon Using Pulsed ENDOR
We demonstrate the electrical detection of pulsed X-band Electron Nuclear
Double Resonance (ENDOR) in phosphorus-doped silicon at 5\,K. A pulse sequence
analogous to Davies ENDOR in conventional electron spin resonance is used to
measure the nuclear spin transition frequencies of the P nuclear spins,
where the P electron spins are detected electrically via spin-dependent
transitions through Si/SiO interface states, thus not relying on a
polarization of the electron spin system. In addition, the electrical detection
of coherent nuclear spin oscillations is shown, demonstrating the feasibility
to electrically read out the spin states of possible nuclear spin qubits.Comment: 5 pages, 3 figure
Electromechanically induced absorption in a circuit nano-electromechanical system
A detailed analysis of electromechanically induced absorption (EMIA) in a
circuit nano-electromechanical hybrid system consisting of a superconducting
microwave resonator coupled to a nanomechanical beam is presented. By
performing two-tone spectroscopy experiments we have studied EMIA as a function
of the drive power over a wide range of drive and probe tone detunings. We find
good quantitative agreement between experiment and theoretical modeling based
on the Hamiltonian formulation of a generic electromechanical system. We show
that the absorption of microwave signals in an extremely narrow frequency band
(\Delta\omega/2\pi <5 Hz) around the cavity resonance of about 6 GHz can be
adjusted over a range of more than 25 dB on varying the drive tone power by a
factor of two. Possible applications of this phenomenon include notch filters
to cut out extremely narrow frequency bands (< Hz) of a much broader band of
the order of MHz defined by the resonance width of the microwave cavity. The
amount of absorption as well as the filtered frequency is tunable over the full
width of the microwave resonance by adjusting the power and frequency of the
drive field. At high drive power we observe parametric microwave amplification
with the nanomechanical resonator. Due to the very low loss rate of the
nanomechanical beam the drive power range for parametric amplification is
narrow, since the beam rapidly starts to perform self-oscillations.Comment: 16 pages, 5 figure
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