Centre National De La Recherche Scientifique

Commissariat a L'energie Atomique Et Aux Energies Alternatives

Tristan Meunier

Maud Vinet

Pierre-André Mortemousque

Gaël Pillonnet

Louis Hutin

Adrien Morel

Gérard Billiot

Benoit Bertrand

Baptiste Jadot

Silvano De Franceschi

Benoît Bertrand

Matias Urdampilleta

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

An elementary cell for a two-dimensional array of quantum dots, said elementary cell extending along a main plane and including: a plurality of sites occupied by quantum dots capable of confining at least one spin qubit and including at least: a first quantum dot, a second quantum dot adjacent to the first quantum dot in a first direction of the main plane, and a third quantum dot adjacent to the first quantum dot in a second direction of the main plane; and a first blocking site adjacent to the second and third quantum dots, towards which a spin qubit cannot be displaced.

Array of quantum dots with spin qubits

A quantum device includes several spin qubits arranged as a matrix and each comprising a quantum dot; several electrometers each electrostatically coupled to a potential well of one of the quantum dots; and circuits for applying an excitation signal to an input electrode of each electrometer. The circuits are configured such that a value of the frequency, phase or maximum amplitude of each excitation signal is different from that of the other excitation signals, and the circuits apply a same excitation signal on electrometers coupled to a same row of qubits. The device also includes a transimpedance amplifier having an input coupled to output electrodes of the electrometers and a demultiplexing circuit including an input electrically coupled to an output of the transimpedance amplifier and configured to demultiplex the output signals to be delivered by the electrometers.

Quantum device with multiplexed electrometer output signals

A device including a semiconductor layer comprising first regions delimited by second regions and third regions; first electrostatic control gates including first conductive portions extending parallel to each other, in vertical alignment with the second regions; second electrostatic control gates including second conductive portions extending parallel to each other, in vertical alignment with the third regions; wherein each first gate includes an electrostatic control voltage adjustment element forming two impedances connected in series, one end of one of the impedances being coupled to the first conductive portion of the first gate and one end of the other of the impedances being coupled to a third conductive portion applying an adjustment electric potential to the second impedance, and wherein the value of at least one of the impedances is adjustable.

Device including elements for compensating for local variability of electrostatic potential

A quantum device with spin qubits, comprising:

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Grenoble, France

Tristan Meunier