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EP-4120145-B1 - ATOMIC QUANTUM PROCESSOR

EP4120145B1EP 4120145 B1EP4120145 B1EP 4120145B1EP-4120145-B1

Inventors

  • Bloch, Immanuel Felix
  • GROSS, CHRISTIAN

Dates

Publication Date
20260506
Application Date
20210712

Claims (11)

  1. A system for performing quantum operations comprising an optical superlattice and a plurality of optical tweezers, wherein the system further comprises means for controlling the optical superlattice; the optical superlattice comprises a plurality of main sites; each main site comprises a storage site and an auxiliary site, each of the storage site and the auxiliary site is configured to hold an atom; the means for controlling the optical superlattice are configured to merge the storage site and the auxiliary site of each main site in parallel by modifying the optical superlattice; and the plurality of optical tweezers is configured to move atoms provided in the plurality of main sites from one main site to another main site.
  2. The system according to claim 1, wherein the means for controlling the optical superlattice are further configured to merge the storage site and the auxiliary site of each main site for a predetermined amount of time by modifying the optical superlattice; and the means for controlling the optical superlattice are configured to separate the storage site and the auxiliary site of each main site after the predetermined amount of time by modifying the optical superlattice.
  3. The system according to claim 1 or 2, wherein the system further comprises atoms having an approximate SU(2) symmetry.
  4. The system according to any one of claims 1 to 3, wherein the means for controlling the optical superlattice are configured to merge the storage site and the auxiliary site of each main site by modifying the optical superlattice such that the storage site and the auxiliary site of each of the main sites form an interaction site that is configured to hold up to two atoms.
  5. The system according to any one of claims 1 to 4, wherein the system further comprises equipment for realizing the optical superlattice; equipment for realizing the plurality of optical tweezers; and means for controlling the plurality of optical tweezers.
  6. The system according to claim 5, wherein the equipment for realizing the optical superlattice comprises lasers configured to output counter-propagating laser beams, wherein a commensurate wavelength ratio of the wavelengths of the lasers is 2; and cooling means configured to cool atoms to sub-Kelvin temperatures.
  7. The system according to claim 5 or 6, wherein the equipment for realizing the plurality of optical tweezers comprises lasers, each configured to output a focused beam such that an atom can be confined with a beam waist of the laser.
  8. The system according to any one of claims 1 to 7, wherein the means for controlling the optical superlattice are configured to change the potential depth and the periodicity of the superlattice.
  9. The system according to any one of claims 5 to 8, wherein the means for controlling the plurality of optical tweezers include at least one spatial light modulator configured to move atoms in the optical superlattice.
  10. A method for performing quantum operations in a system according to claim 1, the method comprising the steps of: merging the storage site and the auxiliary site of each main site in parallel; and moving atoms provided in the plurality of main site from one main site to another main site.
  11. A method of providing a service for performing a quantum operation, the method comprising the steps of: receiving a problem to be solved through the quantum operation, executing the method for performing the quantum operation according to claim 10, thereby obtaining a solution to the problem, providing the solution to the problem as a product of the provided service.

Description

Technical Field The present invention relates to a quantum processor architecture. Corresponding implementations relate to a system for performing quantum operations and a method for performing quantum operations. The present invention can, for example, find an application in the growing sector of quantum technology, in particular in the fields of quantum computing and quantum simulation. Technical Background In the expanding field of quantum technologies, two important hurdles to be overcome for paving the way for industrial applications are the issue of decoherence and the possibility of scalability. The issue of decoherence relates to the problem that quantum systems have the tendency to decohere when interacting with an environment, thereby losing information and in turn reducing their possibility to harness the quantum effect whose exploitation lies at the core of all quantum technologies. The question of scalability relates to the circumstance that in order to properly make use of quantum effects in an application scenario of technological interest often a single atom, ion or the like that can be controlled at will is not sufficient. Instead, many applications in the field of quantum technologies require a large number of elements, that is, a large number of atoms, ions or the like. Thus, it is important that a system cannot only control one element to a high degree but also can be scaled up to many more elements, if possible, arbitrary many and further, if possible, without any or at least without significant overhead when increasing the number of elements. Scalability, however, does not only relate to the question of providing a system of many elements but also to the control these many elements, if possible at the same time. It is clear that a system with many elements that can be addressed, controlled and manipulated only one-by-one in a sequential fashion will likely be at least impracticable. Taken together, a system is required in which many constituents can be put together, all of these constituents can be controlled individually but in a parallel fashion while at the same time the effects of decoherence are controlled and suppressed as well. From T. Calarco et al.: "Quantum computations with atoms in optical lattices: Marker qubits and molecular interactions", Physical Review A, vol. 70, no. 1, 1 July 2004, a scheme for quantum computation with neutral atoms based on the concept of "marker" atoms is known. From U. Dorner et al.: "Quantum logic via optimal control in holographic dipole traps; Quantum logic via optimal control in holographic dipole traps", Journal of Optics B, vol. 7, no. 10, 1 October 2005, a scheme for a quantum logic with neutral atoms stored in an array of holographic dipole traps is known. From Annabelle Bohrdt et al.: "Multiparticle interactions for ultracold atoms in optical tweezers: Cyclic ring-exchange terms", arxiv.org, arXiv:1910:00023, 30 September 2019, a protocol for implementing a SU(N) invariant multi-body interactions in optical tweezer arrays is known. From Christof Weitenberg et al.: "A quantum computation architecture using optical tweezers", arxiv.org, 13 July 2011, a complete architecture for scalable quantum computation with ultracold atoms in optical lattices using optical tweezers focused to the size of a lattice spacing is known. Summary The above problems are solved by the subject-matter of the independent claims. Further preferred embodiments are given by the subject-matter of the dependent claims. Brief Description of the Drawings Embodiments of the present invention will now be described with reference to the figures in which: Figs. 1A-Bshow schematic configurations of a system using an architecture according to an embodiment of the present invention,Figs. 2A-Dshow steps of a parallel quantum operation according to an embodiment of the present invention, andFig. 3shows a flow diagram of a parallel quantum operation according to an embodiment of the present invention. Detailed Description A quantum operation architecture based on collisional quantum gates between neutral atoms is introduced. This architecture may be used at least for quantum computations as well as quantum simulations. Figs. 1A-B show schematic configurations of a system using an architecture according to an embodiment of the present invention. In detail, Fig. 1A shows a schematic view of an optical lattice including an optical superlattice potential filled with atoms and Fig. 1B shows a schematic view of the of the optical lattice where main and auxiliary sites are occupied. In the following the experimental setup as well as preparatory steps therefore are described with reference to these figures. First, a beam of neutral atoms is produced and slowed down such that it can be captured in a magneto-optical trap. A magneto-optical trap uses laser cooling and a spatially varying magnetic field to trap the atoms, thereby being able to produce samples of cold trapped neutral atoms. Tem