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WO-2026093818-A1 - CONTROLLABLE MODULE FOR MANIPULATION OF A QUDIT, QUANTUM PROCESSOR COMPRISING SAID MODULE

WO2026093818A1WO 2026093818 A1WO2026093818 A1WO 2026093818A1WO-2026093818-A1

Abstract

The present invention relates to a controllable module for manipulation of a qudit, characterized in that it comprises: a multimodal waveguide (10) with square cross-section comprising a modulating geometric modification (24, 24a, 24b, 24c) localized on said waveguide, where the modulating geometric modification (24, 24a, 24b, 24c) is controllable to manipulate the modes of the qudit.

Inventors

  • TAMBURINI, Fabrizio
  • SIAGRI, ROBERTO

Assignees

  • ROTONIUM SRL

Dates

Publication Date
20260507
Application Date
20250908
Priority Date
20241029

Claims (20)

  1. 1. Controllable module for manipulation of a qudit, characterized in that it comprises: - a multimodal waveguide (10) with square crosssection comprising a modulating geometric modification (24, 24a, 24b, 24c) localized on said waveguide, where the modulating geometric modification (24, 24a, 24b, 24c) is controllable to manipulate the qudit modes.
  2. 2. Controllable module according to claim 1, characterized in that said manipulation comprises at least one phase variation.
  3. 3. Controllable module according to claim 1 or 2, characterized in that said modulating geometric modification can be controlled to generate or vary said manipulation on command.
  4. 4. Controllable module according to any of claims 1 to 3, characterized in that said manipulation comprises a multimodal conversion simultaneously of "d" modes of a single quantum supported by said waveguide.
  5. 5. Controllable module according to any of claims 1 to 4, characterized in that said module (2) comprises control means (27) comprising means for local thermal deformation of the waveguide (10) or inserts placed locally in the waveguide where the inserts are of active material controllable piezoelectrically, said control means being configured to generate or modify on command said modulating geometric modification (24, 24a, 24b, 24c) .
  6. 6. Controllable module according to any of the preceding claims, characterized in that said waveguide with square cross-section is configured to support at least 6 propagation modes of a quantum, where at least 4 modes are distinguished two by two at least based on two polarizations .
  7. 7. Module according to claim 6, characterized in that the at least 6 modes supported by the waveguide are the following: A= TE10, or a TM mode alternative to TE10, associated with a polarization B= TE01, or a TM mode alternative to TE01, associated with a polarization different from the polarization of A Cl= (CAM L=+l) associated with a polarization C2= (0AM L=+l) associated with a polarization different from the polarization of 01 Dl= (0AM L=-l) associated with a polarization D2= (OAM L=-l) associated with a polarization different from the polarization of DI
  8. 8. Controllable module according to any of the preceding claims, characterized in that the modes supported by the waveguide and manipulable by said modulating geometric modification (24, 24a, 24b, 24c) are more than 6 comprising higher propagation modes with OAM values greater than 1 and lower than -1.
  9. 9. Qudit comprising at least the following propagation modes of a quantum: A= TE10, or a TM mode alternative to TE10, associated with a polarization B= TE01, or a TM mode alternative to TE01, associated with a polarization different from the polarization of A Cl= (OAM L=+l) associated with a polarization C2= (OAM L=+l) associated with a polarization different from the polarization of 01 Dl= (OAM L=-l) associated with a polarization D2= (OAM L=-l) associated with a polarization different from the polarization of DI
  10. 10. Qudit according to claim 9, characterized in that the propagation modes are in number greater than 6 comprising higher propagation modes with 0AM values greater than 1 and lower than -1 where for each of said 0AM values there are two modes with polarizations different from each other.
  11. 11. Input register of a quantum processor characterized in that it comprises one or more information units in the form of qudit according to claim 9 or 10.
  12. 12. Quantum processor comprising: - at least one of said controllable modules (2) according to any of claims 1 to 8; - at least one input register (5) of information units corresponding to said qudit of claim 9 or 10 with at least 6 states placed at the input of said controllable module - at least one output register (15) placed at the output of said controllable module and configured to decode the information corresponding to the manipulated modes .
  13. 13. Processor according to claim 12, characterized in that it comprises a plurality of said controllable modules (2) where the respective modulating geometric modifications (24a, 24b, 24c) of said modules are localized on the same waveguide, therefore called common waveguide (10) .
  14. 14. Processor according to claim 12 or 13, characterized in that it is configured to generate, or to form at least part of, at least one among: - a C-NOT gate - a CC-NOT gate - a Hadamard gate
  15. 15. Processor according to any of claims 12 to 14, characterized in that it comprises a plurality of paths in series or parallel, each comprising at least one of said controllable modules (2) , and connected to one another by respective controllable switches (88) .
  16. 16. Quantum calculation procedure, characterized in that it comprises the following phases: - providing at least one processor according to any of claims 12 to 15; - making at least one photon travel through said controllable module (2) and modifying its states by controlling the modulating geometric modification (24a, 24b, 24c) of said controllable module.
  17. 17. Quantum calculation procedure according to claim 16, characterized in that the processor is according to claim 13 and the modification of the photon states is performed by controlling the plurality of modulating geometric modifications placed on the common waveguide .
  18. 18. Quantum calculation procedure according to claim 17, characterized in that said common waveguide defines a path among a plurality of paths in series and in parallel of said processor, connected by controlled switches (88) , where the procedure comprises a phase of path entanglement obtained by controlling said controllable switches (88) .
  19. 19. Quantum apparatus comprising at least one quantum calculation circuit (50) and one quantum correction circuit (52) at the output of the quantum calculation circuit (50) , where at least the correction circuit (52) comprises at least one controllable module (2) according to any of claims 1 to 8; the apparatus also comprising diagnostic means (55) configured to establish whether at least one calculation performed by the calculation circuit (50) has a discrepancy with respect to an expected result, and to command the correction circuit to compensate said discrepancy by controlling said module.
  20. 20. Quantum calculation correction procedure characterized by the following phases: - providing a quantum apparatus (1) according to claim 19; - performing at least one quantum calculation by means of the calculation circuit (50) , - detecting any calculation discrepancies of the quantum circuit with respect to an expected result; performing a correction of the calculation results of the calculation circuit (50) through said correction circuit (52) based on said discrepancy.

Description

Title : Controllable module for manipulation of a qudit , quantum processor comprising said module . DESCRIPTION The present invention relates to a controllable module for manipulation of a qudit and to a quantum processor comprising said module . The invention has been developed with particular attention to the reali zation of a quantum apparatus , for example a quantum computer, however other applications are not excluded, such as for example the reali zation of a classical computer, where it nevertheless allows reduced consumption and higher calculation speed than current computers based on bit calculation . DEFINITIONS A "quantum apparatus" comprises at least one "quantum circuit" , for example part of a quantum processor , configured to perform a quantum calculation so as to generate output data . The output data may be of quantum type ( qubit ) , classical type (bit ) , or their extensions , such as qudits or their combinations, generally in string form. The quantum circuit also has input data which preferably comprise classical data, such as bits, objects, events, symbols or signals also in quantum regime, generally in string form. The quantum calculation is used to construct the output data based on input data. Quantum apparatuses may comprise a quantum computer, a network thereof, a quantum data transmission device, sensors, classical and combinations thereof, or a network thereof . The definition of quantum apparatus also includes quantum cryptographic systems, possibly coupled with other "classical" devices, suitable for generating cryptographic keys or sequences of objects, events, or symbols . The concept of "event" is understood as a generic physical manifestation that occurs within the Universe or possible Multiverses or even more abstractly in Metaverses . It is therefore understandable how, for example, the apparatus can be a quantum sensor, and the quantum calculation is in this case a measurement. Each one of these quantum apparatuses is realized on relative hardware parts, herein defined as supporting hardware apparatuses. A quantum apparatus may contain a single quantum circuit or a set of them. A quantum processor is a processor dominated or regulated by the laws that we associate with quantum mechanics, meaning any processor capable of performing at least one "quantum calculation". The quantum processor may comprise one or more quantum circuits. By quantum calculation we mean "any process performed by a quantum circuit" such as, for example, any of the following operations based on the laws of quantum mechanics: measuring, generating, manipulating quantum states, sequences of symbols derived from them, et similia, without further restrictions. Quantum calculation is traditionally based on a basic unit called qubit, i.e., the quantum information unit described by a superposition of two states. Quantum calculation can also be based on extensions of qubits. For example we know the qudit, i.e., the quantum information unit described by a superposition of a plurality of states, where the number of states is an integer greater than two (Wikipedia) . We also know the qutrit, i.e., the quantum information unit described by a superposition of three states, which is therefore a three-state qudit. Qubits are for example states of subatomic particles such as photons or electrons, where since every particle, for the superposition principle, can be simultaneously, and with different probabilities, in multiple different states, it is possible to "overcome" the dualism of classical binary codes 0/1 and to convey much more information, thus being able to perform multiple operations simultaneously. TE : We shall define as TE waves the electromagnetic waves that have only electric field components perpendicular to the direction of propagation of the electromagnetic wave (i.e., components in an x and y plane) . TE modes are often indicated as TEmn, where m and n are mode indices representing the number of nodes along the x and y directions respectively. A=TE10 = fundamental electric mode B=TE01 = second-order electric mode 0= (0AM L=+l) = positive orbital angular momentum of value +1 D= (0AM L=-l) = negative orbital angular momentum of value -1 And subsequent modes of orbital angular momentum. More generally: 0AM = Orbital angular momentum SAM = Spin angular momentum STATES = quantum states associated with the photon MODES = decomposition of electromagnetic fields into fundamental modes of the waveguide where the TE mode is the transverse electric mode, and the TM mode is the transverse magnetic mode. VORTEX = mode with non-zero orbital angular momentum OAM, i.e., with L different from zero. L(+l) and L (— 1) identify the OAM modes that in the literature have orbital angular momentum L=+l and L=-l. In extended form we therefore indicate with OAM L(+l) the OAM mode with L=+l, and with OAM L ( — 1) the OAM mode with L=-l. Said modes are alternatively also indicated as OAM (L=+l) and OAM (L=-l) or