(color online) Experimental demonstration of hybrid qubits. (a) Schematic diagram of the physics underlying transitions between |0〉 and |1〉. Dashed green arrows connect |0〉 and |1〉 with |E〉, and the effective transition between the two basis states is indicated by the solid green arrow. ε_A and ε_B mark the detunings where transitions happen. (b) SEM image of a device fabricated for hybrid qubits.^[72] is denoted by a red arrow while S1, S2 and D1, D2 denote source and drain. (c) The Larmor precession of the hybrid qubit working at the (2,3)–(1,4) charge transition.^[72] Charge oscillations are depicted in i as a function of the nonadiabatic pulse width and ε_t (ε_t is defined as the energy detuning relative to the anticrossing point between the qubit levels), while ii shows the signal along the green dashed lines plotted in i. The green solid line in ii is a numeral fit and from which a dephasing time of ns can be extracted.