Commissariat a L'energie Atomique Et Aux Energies Alternatives

Centre National De La Recherche Scientifique

Baptiste Jadot

Yvain Thonnart

Franck Badets

Gérard Billiot

Tristan Meunier

Pierre-André Mortemousque

Matias Urdampilleta

Quentin Schmidt

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.

Device for reading and decoding quantum information

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 Γ relative to the potential barrier separating the two quantum dots and a second parameter ε 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.

Method for reading the spin state of a system and associated method for determining the fidelity

The circuit is connected to the quantum circuit by bias lines and includes a digital-to-analog converter—DAC delivering an analog voltage; memory cells, connected in parallel at the output of the DAC, each memory cell including a switch and a capacitor, 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 the memory cell and which runs parallel to a neighboring bias line.

Electronic circuit for driving a quantum circuit and associated quantum computer

Growing community of inventors

GRENOBLE, France

Baptiste Jadot