  Quantum sensing utilizes quantum systems as sensors to capture weak signal,
and provides new opportunities in nowadays science and technology. The
strongest adversary in quantum sensing is decoherence due to the coupling
between the sensor and the environment. The dissipation will destroy the
quantum coherence and reduce the performance of quantum sensing. Here we show
that quantum sensing can be realized by engineering the steady-state of the
quantum sensor under dissipation. We demonstrate this protocol with a
magnetometer based on ensemble Nitrogen-Vacancy centers in diamond, while
neither high-quality initialization/readout of the sensor nor sophisticated
dynamical decoupling sequences is required. Thus our method provides a concise
and decoherence-resistant fashion of quantum sensing. The frequency resolution
and precision of our magnetometer are far beyond the coherence time of the
sensor. Furthermore, we show that the dissipation can be engineered to improve
the performance of our quantum sensing. By increasing the laser pumping,
magnetic signal in a broad audio-frequency band from DC up to 140 kHz can be
tackled by our method. Besides the potential application in magnetic sensing
and imaging within microscopic scale, our results may provide new insight for
improvement of a variety of high-precision spectroscopies based on other
quantum sensors.
