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DE-102024132814-A1 - MICROWAVE ANTENNA AND QUANTUM COMPUTER SYSTEM

DE102024132814A1DE 102024132814 A1DE102024132814 A1DE 102024132814A1DE-102024132814-A1

Abstract

A microwave antenna (1) for emitting electromagnetic radiation, which is provided to at least one ion (3) for quantum computations, is specified, comprising - a plurality of antenna elements (2) arranged apart from each other, wherein - at least some of the antenna elements (2) are connected to a respective signal line (14), and - each of the respective signal lines (14) is designed to be connected to a respective signal generator. Furthermore, a quantum computer system is specified.

Inventors

  • Reza Arkani
  • Theeraphot Sriarunothai

Assignees

  • eleQtron GmbH

Dates

Publication Date
20260513
Application Date
20241111

Claims (10)

  1. Microwave antenna (1) for emitting electromagnetic radiation which is provided to at least one ion (3) for quantum computing, comprising - a plurality of antenna elements (2) which are spaced apart from one another, wherein - at least some of the antenna elements (2) are connected to a respective signal line (14), and - each of the respective signal lines (14) is configured to be connected to a respective signal generator.
  2. microwave antenna (1) according Claim 1 , wherein - at least some of the antenna elements (2) are controllable independently of each other.
  3. microwave antenna (1) according to one of the Claims 1 or 2 , wherein - the antenna elements (2) are designed to emit electromagnetic radiation, and - the emitted electromagnetic radiation comprises a near-field region (5) in which the ion (3) is designed to be arranged.
  4. microwave antenna (1) according Claim 3 , wherein - the emitted electromagnetic radiation of an ion trap (3) is provided with at least two registers, - each register is configured to capture at least one ion (3), and - at least some of the antenna elements (2) are controllable such that the near field area is controllable to be located in at least one of the registers.
  5. microwave antenna (1) according to one of the Claims 3 or 4 , where - the emitted electromagnetic radiation constructively interferes in the near field.
  6. microwave antenna (1) according to one of the Claims 1 until 5 , wherein - the antenna elements (2) are arranged at grid points of a grid.
  7. microwave antenna (1) according to one of the Claims 1 until 5 , wherein - the signal generators are configured to be connected to a master clock (7).
  8. microwave antenna (1) according to one of the Claims 1 until 7 , wherein - the signal generators are designed to be connected to a controller (8).
  9. quantum computer system (10), comprising - the microwave antenna (1) according to one of the Claims 1 until 8 , and - an ion trap (4) designed to provide the at least one ion (3).
  10. quantum computer system (10) according to Claim 9 , further comprising - a cryostat configured to provide a cryogenic environment, wherein - the microwave antenna (1) and the ion trap (4) are arranged within the cryogenic environment.

Description

The present disclosure relates to a microwave antenna for emitting electromagnetic radiation, which is provided to at least one ion for quantum computing, and a quantum computer system. Typically, in microwave-controlled trapped ion qubits, each trapped ion is driven by a microwave pulse, e.g., a microwave field with a predetermined frequency, amplitude, and phase. The ratio between the achievable microwave field strength and the applied power limits the gate speed or the number of qubits due to dissipative heating of the ion trap, which is particularly critical for operating the ion trap in a cryogenic environment. One task to be solved is the provision of a microwave antenna with an improved magnetic field distribution. Furthermore, a quantum computer system is to be provided. The problem is solved by the subject matter of the independent claims. Advantageous embodiments, implementations, and further developments are the subject matter of the respective dependent claims. According to at least one embodiment, the microwave antenna is configured to emit electromagnetic radiation that is provided to at least one ion for quantum computing. For example, the microwave antenna is configured to provide electromagnetic radiation to an ion trap with a processing area. The processing area is specifically configured to accommodate at least one ion, for example, a plurality of ions. For example, at most 100 ions or at most 60 ions are provided in the processing area. For example, the microwave antenna is configured to provide the electromagnetic radiation to the ions in the processing area. The ion trap can be a Paul trap, a linear ion trap, a surface ion trap, or a multilayer ion trap. The ion trap comprises, for example, a set of electrodes configured to trap and/or manipulate at least one ion within a processing area. For instance, a high-frequency voltage is applied to at least some of the electrodes in the electrode set, creating a time-varying electric field within the processing area that is configured to trap and/or manipulate the ion. For example, the ion intersects a trapping axis and/or oscillates around a trapping axis within the processing area. For example, electromagnetic radiation, in particular microwave radiation, is applied to at least some trapped ions, especially by the microwave antenna. The electromagnetic radiation is configured, for example, to induce a transition between the energy levels of at least some of the trapped ions. For example, by applying the electromagnetic radiation, an operation is performed on the quantum states of the trapped ions, such as qubit rotations or state preparations. Microwave radiation is particularly characteristic of electromagnetic radiation with a frequency of at least 0.1 GHz and at most 500 GHz, and especially at least 0.3 GHz and at most 300 GHz. The ion trap comprises, for example, at least one magnet arrangement configured to generate a magnetic field in the processing area. This magnet arrangement may include at least one permanent magnet arrangement and/or at least one coil. The magnet arrangement is, for example, spaced laterally and/or vertically from the processing area. In particular, the magnet arrangement is configured to generate a gradient of magnetic field strength in the processing area, e.g., along the capture axis. This is because the magnetic field of the magnet arrangement has different strengths for different positions in the processing area and, in particular, for different positions along the capture axis. Advantageously, when there are a large number of ions in the processing area, the resonance frequency of each of the ions on which the size gradient of the magnetic field of the magnet arrangement acts is unique for each ion in the processing area. According to at least one embodiment, the microwave antenna comprises a plurality of antenna elements spaced apart from one another. The antenna elements are, for example, planar and have a principal plane of extension that extends in lateral directions. For example, each antenna element is formed by a flat metal plate. Each flat metal plate has, for example, a round, elliptical, or polygonal shape, e.g., triangular or quadrilateral. In particular, directly adjacent antenna elements are not in direct and immediate contact with each other. For example, a minimum distance is directly The distance between adjacent antenna elements in lateral directions is at most 5 mm, at most 3 mm, or at most 2 mm, approximately 1 mm. For example, the minimum distance between directly adjacent antenna elements is at least 0.1 mm or at least 0.5 mm. The antenna elements comprise, for example, an electrically conductive material. In particular, the antenna elements comprise or consist of a metal. For example, the minimum spacing is characteristic of the angular resolution of the microwave antenna. The angular resolution is particularly characteristic of the width of a main lobe of the radiated electromagnetic r