My new paper with Prof. Nan Zhao was posted on the arXiv yestoday: arXiv:1311.2266. The paper proposed the scheme to detect the tiny mass changing with optically levitated nanodiamond. With the dynamical decoupling method, the mass of the oscillator can be measured by detecting the coherence of the Nitrogen-vacancy center in the nanodiamond. The most suprise feature of the method is that the detecting efficiency is higher in the high temperature than in the low temperature. We believed that the scheme can be used for detecting the mass of single small molecule in room temperature. The title and abstract of the paper is as follows,
Room-temperature ultra-sensitive mass spectrometer via dynamic decoupling
We propose an ultra-sensitive mass spectrometer based on a coupled quantum-bit-oscillator system. Under dynamical decoupling control of the quantum bit (qubit), the qubit coherence exhibits a comb structure in time domain. The time-comb structure enables high precision measurement of oscillator frequency, which can be used as an ultra-sensitive mass spectrometer. Surprisingly, in ideal case, the sensitivity of the proposed mass spectrometer, which scales with the temperature T as T−1/2, has better performance in higher temperature. While taking into account qubit and oscillator decay, we show that the optimal sensitivity is independent on environmental temperature T. With present technology on solid state spin qubit and high-quality optomechanical system, our proposal is feasible to realize an ultra-sensitive mass spectrometer in room temperature.