Double-island single-electron transistor operated at radio-frequency for sensitive and fast charge detection

We present a double-island single-electron transistor operated at radio-frequency (rf-DISET) for fast and highly sensitive detection of charge motion in the solid state. The devices were fabricated using electron-beam lithography and a standard shadow-mask evaporation technique. Fast operation was made possible by including a DISET in an impedance-matching tank circuit. Well above 1/f noise this DISET exhibited an excellent charge sensitivity of 5.6×10-6e/Hz. We present time-domain measurements of small charge signals (⩽0.1e) made on μs timescales, and show results that indicate our entire system has a noise temperature of just 2.1 K.