EP-4740225-A1 - SYSTEMS AND METHODS FOR INTERACTING WITH A MATTER PARTICLE

EP4740225A1EP 4740225 A1EP4740225 A1EP 4740225A1EP-4740225-A1

Abstract

There is presented, a system (2) for forming a plurality of focussed electromagnetic, EM, radiation regions, for interacting with one or more matter particles; the matter particles act as qubits in a quantum computation. The system comprising: I) a source assembly (8) comprising a plurality of sources (10) wherein each source is configured to generate and output EM radiation (12); the plurality of sources comprising at least a first source and a second source; the source assembly configured to independently change the intensity of the EM radiation, generated by the first and second sources, output from the source assembly; II) a focussing assembly comprising one or more EM focussing elements; the focussing assembly configured to focus EM radiation to form: a first focussed EM region, of the plurality of EM regions (14), using EM radiation output from the first source; a second focussed EM region, of the plurality of EM regions, using EM radiation output from the second source. The first EM region occupying a different portion of space to the second EM region; wherein: a) the source assembly is configured such that the first and second sources are upon a unitary device.

Inventors

DREON, Davide
FAVIER, PIERRE
NGUYEN, CATHERINE

Assignees

Pasqal

Dates

Publication Date: 20260513
Application Date: 20240708

Claims (14)

1. A system for forming a plurality of focussed electromagnetic, EM, radiation regions, for interacting with one or more matter particles, wherein the matter particles are neutral atoms; the matter particles acting as qubits in a quantum computation; the system comprising: I) a source assembly comprising a plurality of sources wherein each source is configured to generate and output EM radiation comprising a wavelength in the visible or near infrared spectrum; the plurality of sources comprising at least a first source and a second source; the source assembly configured to independently change the intensity of the EM radiation, generated by the first and second sources, output from the source assembly; II) a focussing assembly comprising one or more EM focussing elements; the focussing assembly configured to focus EM radiation to form: a first focussed EM region, of the plurality of EM regions, using EM radiation output from the first source; a second focussed EM region, of the plurality of EM regions, using EM radiation output from the second source; the first EM region occupying a different portion of space to the second EM region; wherein the source assembly is configured such that the first and second sources are upon a unitary device.
2. The system of claim 1, wherein the source assembly further comprises a plurality of outputting components, the outputting components configured to output EM radiation from the source assembly.
3. The system of claim 2, wherein the plurality of outputting components comprise a two- dimensional array of outputting components.
4. The system of claim 3, wherein the outputting components are configured to output the EM radiation out-of-plane of the two dimensional array of outputting components.
5. The system of any preceding claim wherein the EM regions overlap in space.
6. The system as claimed in claim 5 wherein the overlapping EM regions form a composite EM trap to hold one or more of the matter particles.
7. The system as claimed in claim 6 wherein the system further comprises: a) a first EM modulator for receiving EM radiation generated by the first EM source; b) a second EM modulator for receiving EM radiation generated by the second EM source; c) an electronic controller configured to output: I) a first set of signals to the first and second EM modulators; and, II) a second set of signals to the first and second EM modulators; wherein, the first set of signals is configured to drive the said EM modulators to output EM radiation to form the composite trap for holding the said one or more matter particles in a first position in space; the second set of signals is configured to drive the said EM modulators to output EM radiation to form the composite trap for holding the said one or more matter particles in a second position in space that is different to the first position; the system configured to output the second set of signals after outputting the first set of signals.
8. The system as claimed in claim 7 wherein: the first set of signals comprises a first signal for the first EM modulator and a first signal for the second EM modulator; the second set of signals comprises a second signal for the first EM modulator and a second signal for the second EM modulator; the first signal for the first EM modulator is configured to drive the first EM modulator to output EM radiation forming the first focussed EM region at a first intensity; the first signal for the second EM modulator is configured to drive the second EM modulator to output EM radiation forming the second focussed EM region at a second intensity; the second signal for the first EM modulator is configured to drive the first EM modulator to output EM radiation forming the first focussed EM region at a third intensity; the first signal for the second EM modulator is configured to drive the second EM modulator to output EM radiation forming the second focussed EM region at a fourth intensity; the first intensity is greater than the third intensity; the fourth intensity is greater than the second intensity.
9. The system as claimed in claim 8 wherein: the first set of signals forms a first composite trap at a first time; the second set of signals forms a second composite trap at a second time after the first time; the first and second composite traps at least partially overlapping in space.
10. The system as claimed in any preceding claim wherein the EM radiation output from the said EM modulators is for controlling at least one qubit state transition of the quantum computation.
11. The system as claimed in any preceding claim wherein: the system comprises a set of one or more further sources for controlling at least one qubit state transition of the quantum computation; the EM radiation of at least one of the first source or second source being configured to prevent an atomic transition of a matter particle arising from the one or more further sources.
12. The system as claimed in claim 11 wherein the EM radiation of the first and/or second source comprises an off-resonance wavelength of the qubit state transition.
13. The system as claimed in claim 12 wherein the one or more further sources comprises a different wavelength than at least one of the first and second sources.
14. A method of forming a plurality of focussed electromagnetic, EM, radiation regions, for interacting with one or more matter particles, wherein the matter particles are neutral atoms; the matter particles acting as qubits in a quantum computation; the method comprising: I) generating and outputting EM radiation from a source assembly comprising a plurality of sources, wherein the EM radiation comprises a wavelength in the visible or near infrared spectrum; the plurality of sources comprising at least a first source and a second source; the source assembly configured to independently change the intensity of the EM radiation, generated by the first and second sources, output from the source assembly; II) focusing EM radiation, using a focussing assembly comprising one or more EM focussing elements, to form: a first focussed EM region, of the plurality of EM regions, using EM radiation output from the first source; a second focussed EM region, of the plurality of EM regions, using EM radiation output from the second source; the first EM region occupying a different portion of space to the second EM region; wherein the source assembly is configured such that the first and second sources are upon a unitary device.

Description

Systems and methods for interacting with a matter particle Technical Field The present invention is in the field of electromagnetic signals, in particular, but not limited to traps for holding matter particles for quantum computation. Background Matter particles such as ions or neutral atoms may be used in various systems including quantum computation. Such systems typically require matter particles to be held in a particular position whilst an operation is performed on them with an external stimulus such as laser light. One such system is a neutral atom quantum computer wherein different patterns of traps are required to be consecutively set-up. In these systems, atoms are trapped in arrays of optical traps, known as optical tweezers, which are tightly focused laser beams produced by sending a beam into a beam-shaping device and high-numerical aperture optics. A spatial light modulator (SLM) can be used as a suitable beamshaping device, enabling arranging the tweezers in programmable arbitrary geometric patterns in ID, 2D or 3D shapes. Liquid Crystal SLMs are known to be used as beam shaping devices to separate a single laser beam into multiple traps. Another approach is using Acousto-Optic Deflectors (AOD) to generate multiple beams. These current solutions have slow refresh rates of the device when different geometrical patterns need to be used in succession. In addition, current prior art solutions do not provide individual addressability of the sites in a given pattern. The existing alternative solutions have limitations. AODs have the problem of not being adapted to arbitrary geometrical patterns (if not done by time multiplexing) and the addressability also must be done either by entire columns or by lines since the deflections are applied subsequently. Digital micromirrors devices (DMD) have a higher refresh rate but not sufficient for many applications, and they are limited in optical power efficiency. Grimm et al., "Optical Dipole Traps for Neutral Atoms", 42, 2000, 95-170 discusses methods for trapping atoms and experimental techniques for optical traps. Nogrette et al., "Single-Atom Trapping in Holographic 2D Arrays of Microtraps with Arbitrary Geometries", Phys. Rev. X 4, 021034 discusses arrays generated using a spatial light modulator and an optical dipole-trap beam for trapping single rubidium atoms. The trapping methods disclosed in these documents do not provide individual addressability of the trapping sites. WO2021/112948 describes optical holographic addressing of atomic quantum bits. In the background section of this document there is described arrays of vertical -cavity surface-emitting lasers (VCSELs) for visible light, along with the limitations of using VCSELs for such a system. In paragraph 0060, WO2021/112948 briefly describes, with respect to figure 7 of the same document, using an array of coherent light sources, such as VCSELs, where each laser is actuated to produce a corresponding spatial-mode distribution. WO2021/112948 does not provide an enabling disclosure for how to use VCSELs in such a system. Summary This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. In a first aspect there is presented a system (2) for use in a quantum computation; the system (2) comprising: I) a chamber (4) for accommodating a plurality of spatially separated matter particles (6) for use as qubits in the quantum computation; II) a source assembly (8) comprising a plurality of surface-emitting electromagnetic, EM, sources (10) configured to output EM radiation (12); the system (2) configured to form a plurality of regions (14) of the EM radiation in the chamber (4), wherein at least two (16) of the plurality of regions (14) are for interacting with at least one of the spatially separated matter particles (6). In other words, at least a first and second region (16) of the plurality of regions (14) are each for interacting with at least one of the spatially separated matter particles (6). For example, both regions may interact with the same one (or more) matter particles, or each region may interact with one (or more) different matter particles. The system of the first aspect may be adapted according to any suitable way disclosed herein, including but not limited to any one or more of the following options. It is to be understood that any of the following options may be combined with any of the examples described elsewhere herein. The system may be configured such that: a first region of the plurality of regions is for trapping a first matter particle; a second region of the plurality of regions is for trapping a second matter particle; the first region being spatially separate to the second region. The system may be configu