Abstract: A quantum device comprising a plurality of qubits, a demultiplexing circuit, a common transmission line for transmitting qubit read signals to the demultiplexing circuit, and, for each qubit of the plurality, one quantum electrometer coupled to the qubit with a view to transmitting, over the common transmission line, a signal depending on a current state of the qubit and on a periodic excitation applied to the quantum electrometer. The quantum device is noteworthy in that, the periodic excitations transmitted to a group of qubits of the device being transmitted with an identical frequency, the device comprises phase-shifting means that introduce distinct phase shifts and optionally amplitude-attenuating means that introduce amplitude differences into the excitations respectively applied to the various quantum electrometers.

Abstract: The circuit is connected to the quantum circuit by bias lines and includes a digital-to-analog converter-DAC delivering an analog voltage (Ve); memory cells, connected in parallel at the output of the DAC, each memory cell including a switch (I1, I2, I3, I4) and a capacitor (C1, C2, C3, C4), the capacitor storing a level of potential at which to maintain a bias line connected to the output of the memory cell; and, a device for generating control signals generating, in synchronization with the DAC, a control signal for each switch of each memory cell, the control signal, a value of the capacitor of a memory cell being selected so as to make negligible a parasitic capacitor affecting the bias line connected to said memory cell and which runs parallel to a neighboring bias line.

Abstract: A method for determining the conversion factor between a voltage applied to the gates of a system and the tunnel coupling ?QD between both quantum dots of the pair of quantum dots, the system including a pair of quantum dots containing two charged particles and including a first quantum dot and a second quantum dot, and the tunnel coupling ?QD between both quantum dots of the pair of quantum dots being modulated using a plurality of gates, a set of voltages applied to the gates of the plurality of gates defining an operating point of the system, the pair of quantum dots being in one charge state from the charge state {2,0}, the charge state {1,1} and the charge state {0,2}, and both charged particles adopting either a singlet spin state S or a triplet spin state T0 or a triplet spin state T+/T?.

Abstract: A method for determining an isolated operating point associated with an isolated regime of a system including first and second subsystems, for which isolated operating point a passage of a charged particle from the first subsystem to the second subsystem and vice versa is forbidden for a reference duration, the first subsystem and/or the second subsystem containing zero, one or more charged particles, a tunnel coupling existing between the first subsystem and the second subsystem, the tunnelling rate allowing exchange of one or more charged particles between the first subsystem and the second subsystem and being modulated by a gate voltage applied to one or more gates configured to form a potential barrier between the first subsystem and the second subsystem, an operating point of the system being determined by the value assumed by each gate voltage, this tunnel coupling being further quantified by a tunnelling rate noted ?.

Abstract: A method for determining an optimal spin/charge conversion operating point in a system including a pair of quantum dots including first and second quantum dots, the pair of quantum dots containing two charged particles and adopting a first charge state (2,0) in which both charged particles are in the first quantum dot, a second charge state (1,1) in which each quantum dot contains a charged particle, or a third charge state (0,2) in which both charged particles are in the second quantum dot, the charge state being a function of the voltage applied to at least two gates, the value of these voltages defining an operating point of the pair of quantum dots; the charged particles adopting a first spin state, called singlet spin state S, or a second spin state, called triplet spin state among the triplet spin state T0 or the triplet spin state T+/T?.

Abstract: A semiconductor device includes a layer of a semiconductor material in which is formed an active zone; a plurality of first gates forming a plurality of lines substantially parallel to each other and covering in part the active zone; a plurality of second gates forming a plurality of columns; at least one third gate, designated measurement gate, extending along an axis substantially parallel to the lines of the plurality of lines and in a direction opposite to the lines of the plurality of lines with respect to the active zone, and a first electrode and a second electrode situated on either side of the plurality of measurement gates in the active zone.

Abstract: A method for manipulating a group of quantum dots of a quantum dots matrix, called target group, each target group including a quantum dot and containing a charged particle, the matrix being connected to a reservoir of charged particles, each target group being defined by a potential barrier, each charged particle being a carrier of a charge and spin, the method including, for each target group, a total isolation procedure of the target group relative to the other quantum dots, the potential barrier separating the target group of quantum dots of the matrix adjacent to the target group being configured so that the charged particle(s) contained in the target group cannot cross the potential barrier in order to be moved to the adjacent quantum dots or to the reservoir even when such a transition is authorised from an energy standpoint; and maintaining the target group in the completely isolated regime.

Abstract: A method of measuring the spin state of two charged particles able to adopt a first, second, third, and fourth spin state S, T+, T0 and T, the two charged particles being contained in a system, including first and second quantum dots characterised by a first parameter ? relative to the potential barrier separating the two quantum dots and a second parameter ? corresponding to the difference in energy between the fundamental states of the first and second quantum dots, the couple formed by the values of these two parameters defining an operating point of the system as a function of which the system adopts a first charge state noted (1,1) wherein each quantum dot contains a charged particle, a second charge state noted (2,0) wherein the first quantum dot contains two charged particles or a third charge state noted (0,2) wherein the second quantum dot contains two charged particles.