2Associative learning in neural networks is crucial and required to relate new experience with existing memories and was first observed by I. Pavlov in his famous dog experiment. 1 Stimulating different senses by the sight of food and the sound of a bell, I. Pavlov trained his dog to correlate salivation with the sound of the bell (association), although at the beginning of the experiment salivation was only triggered by the sight of food. In neural networks, association corresponds to an increase of synaptic strength, which is controlled by action potentials emitted by pre-and postsynaptic neurons. 2,3 Associative learning can be emulated with memristive Hopfield neural networks, 4 memristive circuits 5,6,7,8 or magnetic tunnel junctions. 9 Other demonstrations of associative learning implement two artificial synapses with memristor emulators 10 or a resistor and a memristor. 11 Artificial synapses based on memristors enable synaptic modifications by applying pre-and postsynaptic voltage pulses to the two terminals of the device, 12,13 which allows to combine information storage and processing on the same physical platform. 14,15,16 Owing to the two-terminal character, however, the application of postsynaptic voltage pulses blocks the device output and prevents information to be transferred during the learning process. The devices separate signal transmission and learning. Hence,18,19 or even fourterminal 20 synaptic devices may be beneficial because of their ability to decouple the postsynaptic pulse from the output. Indeed, associative learning with simultaneous learning and signal transmission has been demonstrated with three-terminal synapses based on nano-particle organic memory field effect transistors by applying postsynaptic pulses with amplitudes as large as 30 V to the third terminal. 21 In memristor-synapses, extra terminals may be implemented with additional gates that allow tuning the set voltage with an electric field effect. 22 We report associative learning with Y-shaped quantum dot floating gate transistors operated in memristive modes. The geometry of the devices with two input terminals and one output terminal enables realizing associative learning with postsynaptic voltage amplitudes as low as 0.5 V. The 3 conductance of the Y-shaped quantum dot floating gate transistor depends on the amount of localized charges on quantum dots (QDs) that are precisely positioned in the two input terminals. Emulating external stimuli "food" and "bell" with two input voltages allows implementing an association between "bell" and "salivation". The number of required pulses to develop (association) or to forget (extinction) the correlation between "bell" and "salivation" is controlled by the amplitudes of the input voltages. Connecting the voltage applied to the drain contact (i.e. right branch V r ) with the side gates (see Fig. 1(a)) leads to a memristive operation. 25,26,27 The Y-shaped floating gate transistor is characterized by applying the voltage V r = V l to both branches with resistances of R l = R...