CELL FOR CARRYING OUT QUANTUM OPTICAL MEASUREMENTS

Abstract

A cell (110) for carrying out quantum optical measurements on at least one atom cloud is proposed. The cell (110) comprises a control unit (114) for controlling electric fields at the location (112) of the atom cloud. The control unit (114) comprises: at least one housing (116) having at least one interior (120) for receiving the atom cloud and having at least one opening (122) for introducing the atoms of the atom cloud into the interior (120); and at least two electrodes (118), wherein the electrodes (118), independently of one another, are able to be subjected to electrical potentials and are configured to influence at least one electric field in the interior (120), wherein the electrodes (118) are mechanically connected to the housing (116).

At least one of the electrodes (118) is at least partly formed by at least one optical window (130) through which at least one light beam (132) for interaction with the atom cloud is able to be radiated into the interior (120). The optical window (130) comprises at least one transparent substrate (134) and at least one transparent electrically conductive coating (136) of the substrate (134). Furthermore, a system (182) for carrying out quantum optical measurements on at least one atom cloud, a quantum computer (204) and a method for carrying out quantum optical measurements on at least one atom cloud are proposed.

Claims

1. A cell for carrying out quantum optical measurements on at least one atom cloud, comprising a control unit for controlling electric fields at the location of the atom cloud, wherein the control unit comprises: at least one housing having at least one interior for receiving the atom cloud and having at least one opening for introducing the atoms of the atom cloud into the interior; and at least two electrodes, wherein the electrodes, independently of one another, are able to be subjected to electrical potentials and are configured to influence at least one electric field in the interior, wherein the electrodes are mechanically connected to the housing, wherein at least one of the electrodes is at least partly formed by at least one optical window through which at least one light beam for interaction with the atom cloud is able to be radiated into the interior-, wherein the optical window comprises at least one transparent substrate and at least one transparent electrically conductive coating of the substrate.

2. The cell as claimed in claim 1, wherein the at least one electrode having the at least one optical window comprises at least one holding unit, wherein the holding unit is configured to hold the optical window, wherein the holding unit is furthermore configured to electrically contact the transparent electrically conductive coating.

3. The cell as claimed in claim 2, wherein the holding unit is configured to hold the optical window in a clamping mount, wherein the clamping mount has at least one electrically conductive element which is pressed onto the transparent electrically conductive coating.

4. The cell as claimed in claim 1, furthermore comprising at least two electrical terminals for connection to at least one voltage source, wherein the electrical terminals are electrically connected to the electrodes.

5. The cell as claimed in claim 1, wherein the electrically conductive coating comprises at least one transparent conductive oxide (TCO).

6. The cell as claimed in claim 1, wherein the substrate comprises at least one material selected from the group consisting of quartz glass and borosilicate glass.

7. The cell as claimed in claim 1, wherein the electrodes have at least two optical windows, wherein the optical windows are arranged in such a way that a plurality of light beams are able to be radiated from different directions through the optical windows into the interior.

8. The cell as claimed in claim 1, wherein the housing is at least partly produced from at least one electrically conductive material.

9. The cell as claimed in the preceding claim 1, wherein the electrodes, in addition to the at least one optical window, furthermore have at least one nontransparent electrode, wherein the at least one nontransparent electrode is produced from at least one electrically conductive material and is at least partly integrated into the housing.

10. The cell as claimed in claim 1, furthermore comprising at least one vacuum cell wherein the housing and the electrodes are introduced into the vacuum cell, wherein the vacuum cell has at least one flange for connection to a high-vacuum device.

11. The cell as claimed in claim 10, wherein the optical window is at least partly fixed between the housing and at least one inner wall of the vacuum cell, wherein the optical window is at least partly accommodated in at least one mount, wherein the mount is pressed against the inner wall of the vacuum cell by at least one spring element mounted on the housing.

12. The cell as claimed in claim 10, wherein the vacuum cell is at least partly embodied as a transparent vacuum cell.

13. A system for carrying out quantum optical measurements on at least one atom cloud, comprising at least one cell as claimed in claim 1, furthermore comprising at least one adjustable voltage source, wherein the voltage source is connected to the electrodes and wherein the at least one electric field in the interior of the housing is adjustable by means of the voltage source.

14. A quantum computer, comprising at least one system as claimed in claim 13 relating to a system, furthermore comprising at least one controller unit for addressing and/or reading out quantum bits in an atom cloud in the interior.

15. A method for carrying out quantum optical measurements on at least one atom cloud, comprising the following steps: i. providing at least one system as claimed in claim 13 relating to a system; ii. generating at least one high vacuum at the location of the cell of the system; iii. introducing at least one atom cloud into the interior of the cell; iv. radiating at least one light beam through the at least one optical window of the cell, such that the light beam interacts with the atom cloud in the interior of the cell; and v. subjecting the electrodes of the cell to electrical potentials and adjusting an electric field in the interior by means of the electrodes.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0131] Further details and features will become apparent from the following description of exemplary embodiments, in particular in conjunction with the dependent claims. In this case, the respective features can be realized by themselves or as a plurality in combination with one another. The invention is not restricted to the exemplary embodiments. The exemplary embodiments are illustrated schematically in the figures. In this case, identical reference numerals in the individual figures denote elements that are identical or functionally identical or correspond to one another with regard to their functions.

[0132] Specifically in the Figures:

[0133] FIG. 1 shows a perspective illustration of one exemplary embodiment of a cell according to the invention for carrying out quantum optical measurements on at least one atom cloud;

[0134] FIG. 2 shows a sectional illustration of the exemplary embodiment in accordance with FIG. 1;

[0135] FIG. 3 shows a further sectional illustration of the exemplary embodiment in accordance with FIG. 1, with a sectional plane perpendicular to the sectional plane in FIG. 2;

[0136] FIG. 4 shows a perspective illustration of a further exemplary embodiment of a cell according to the invention for carrying out quantum optical measurements on at least one atom cloud;

[0137] FIG. 5 shows one exemplary embodiment of a facility for contacting electrodes of the exemplary embodiment of the cell according to the invention in accordance with FIG. 4;

[0138] FIG. 6 shows a schematic illustration of one exemplary embodiment of a system according to the invention for carrying out quantum optical measurements on at least one atom cloud;

[0139] FIG. 7 shows a schematic illustration of one exemplary embodiment of a quantum computer according to the invention; and

[0140] FIG. 8 shows a flow diagram of one exemplary embodiment of a method according to the invention for carrying out quantum optical measurements on at least one atom cloud.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0141] FIG. 1 shows a perspective illustration of a first exemplary embodiment of a cell 110 according to the invention for carrying out quantum optical measurements on at least one atom cloud, the location of which within the cell 110 is identified symbolically by the reference sign 112 in the figures. FIGS. 2 and 3 show sectional illustrations of the exemplary embodiment in accordance with FIG. 1. FIGS. 1 to 3 are described jointly below.

[0142] The cell 110 comprises a control unit 114 for controlling electric fields at the location 112 of the atom cloud. The control unit 114 is part of the cell 110 and constitutes an apparatus configured to influence electric fields at the location 112 of the atom cloud within the cell 110 in a targeted manner, for example to increase and/or to decrease them in at least one spatial direction. In this case, the control unit 114 can in particular also act as a Faraday cage and at least substantially shield external electric fields. The control unit 114 comprises at least one housing 116 and at least two electrodes 118.

[0143] The housing 116 comprises at least one interior 120 for receiving the atom cloud. The housing 116 furthermore comprises at least one opening 122 for introducing the atoms of the atom cloud into the interior 120. The atom cloud can be locally restricted in particular in the interior 120 of the cell 110. Furthermore, quantum optical measurements on the atom cloud can be performed in the interior 120. The cell 110 can be configured in particular to shield the quantum optical measurements taking place in it against the environment outside the cell 110, for example against external mechanical forces such as e.g. vibrations, against the ingress of physical matter such as e.g. contaminants, against electromagnetic radiation, against an ambient temperature, against an ambient pressure or against a combination of two or more or all of the influences mentioned.

[0144] The opening 122 for introducing the atoms of the atom cloud into the interior 120 can have for example a round or differently shaped geometry. By way of example, atoms from an atom source can be introduced into the interior 120 through said opening 122. For this purpose, for example, as will be explained in even greater detail below, the cell 110 can be coupled to a vacuum apparatus comprising an atom source. Via at least one connection piece 124, the cell 110 can be connectable to further apparatuses, for example the vacuum apparatus having the atom source. The atoms of the atom cloud can be introduced into the interior 120 for example through a tunnel 125 in the connection piece 124 and the opening 122. The connection piece 124 and thus also the cell 110 can be held and/or moved for example by way of at least one carrier construction 126, wherein the carrier construction 126, as will be explained in even greater detail below, can also be used for electrical contacting.

[0145] The housing 116 can furthermore at least partly consist of at least one electrically conductive material, for example of high-grade steel. In this regard, the housing 116 can have for example walls produced wholly or partly from metal. The housing 116 can have one or more metallic segments 128, for example, which can function in particular as electrodes 118. The metallic segments 128 can be electrically insulated from one another and thereby be able to be subjected to electrical potentials independently of one another.

[0146] The electrodes 118 are able to be subjected to electrical potentials independently of one another. The electrodes 118 are furthermore configured to influence at least one electric field in the interior 120. The electrodes 118 can be arranged spatially with respect to the interior 120 in such a way that field components of the electric field in the interior 120 are able to be influenced in at least one spatial direction, preferably in at least two spatial directions, in particular in three spatial directions, by means of the electrodes 118. In particular, the control unit 114 can be configured in such a way that, by means of the housing 116 and the at least two electrodes 118, a Faraday cage is formed, by way of which the atom cloud is at least partly shielded against electric fields in all three spatial directions and/or by way of which the electric field in the interior 120 is able to be influenced in all three spatial directions by means of the electrodes 118 being correspondingly subjected to electrical potentials. At least two of the electrodes 118 can be arranged on mutually opposite sides in relation to the interior 120. By way of example, the cell 110 can comprise six electrodes 118 distributed around the interior 120 and situated opposite one another in pairs. The electrodes 118 are mechanically connected to the housing 116. As explained, the housing 116 can comprise at least one portion of the electrodes 118. In other words, at least one portion of the electrodes 118 can be integrated into the housing 114.

[0147] At least one of the electrodes 118 is at least partly formed by at least one optical window 130. This means that either this at least one electrode 118 is completely formed by the optical window 130, or that the electrode 118 comprises one or more further components besides the at least one optical window 130. At least one light beam 132 for interaction with the atom cloud is able to be radiated into the interior 120 through the optical window 130. The optical window 130 comprises at least one transparent substrate 134 and at least one transparent electrically conductive coating 136 of the substrate 134. The electrically conductive coating 136 can extend in particular areally over a surface of the substrate 134 facing the interior 120. In other words, the electrically conductive coating 136 can be applied at least to a side of the substrate 134 facing the interior 120. The electrically conductive coating 136 can comprise at least one transparent conductive oxide (TCO), in particular at least one transparent conductive oxide selected from the group consisting of tin oxide and indium tin oxide (ITO). The substrate 134 can comprise at least one material selected from the group consisting of quartz glass and borosilicate glass. The at least one optical window 130 can have a transparency of at least 10%, in particular at least 80% and in particular at least 85% in a wavelength range of 400 nm to 900 nm, in particular in a wavelength range of 300 nm to 1000 nm. The optical window 130 can furthermore have at least one antireflection coating. The antireflection coating can be applied on the side facing away from the interior and/or between the conductive coating and the substrate.

[0148] The at least one electrode 118 with the at least one optical window 130 can be at least partly embodied as a metallic plate 138 having at least one opening 140, in particular as a high-grade steel plate 141. The optical window 130 can at least partly cover the opening 140. The housing 116 can furthermore have at least one opening 142 through which the light beam 132 is able to be radiated into the interior 120. The optical window 130 can be mechanically connected to the housing 116 in such a way that the light beam 132 is able to be radiated into the interior 120 through the optical window 130 and through the opening 142. The opening 142 can penetrate through at least one wall of the housing 116 and taper conically in the direction of the interior 120. The electrodes 118 can have at least two optical windows 130, in particular at least three optical windows 130. The optical windows 130 can be arranged in such a way that a plurality of light beams 132 are able to be radiated from different directions through the optical windows 130 into the interior 120.

[0149] The at least one electrode 118 with the at least one optical window 130 can furthermore comprise at least one holding unit 144. The holding unit 144 can be configured to hold the optical window 130, in particular outside the interior 120 in front of the opening 142. The holding unit 144 can furthermore be configured to contact the transparent electrically conductive coating 136. For this purpose, the holding unit 144 can comprise at least one electrically conductive element, in particular a metal. The holding unit 144 can comprise a clamping mount 146. The holding unit 144 can be configured to hold the optical window 130 in the clamping mount 146. The clamping mount 146 can have at least one electrically conductive element, in particular a metal, which is pressed onto the transparent electrically conductive coating 136. In particular, at least one edge of the optical window 130 can be clamped in the clamping mount 146, such that the light beam 132 can be radiated into the interior 120 through a central portion of the optical window 130. The holding unit 144 can be an integral part of the housing 116. Alternatively or additionally, the holding unit 144 can be connected to the housing 116 via at least one connection element 148, in particular via at least one connection pin 150, for example by means of mechanical springs.

[0150] The cell 110, in addition to the at least one optical window 130, can furthermore have at least one nontransparent electrode 152. The at least one nontransparent electrode 152 can be produced from at least one electrically conductive material and can be at least partly integrated into the housing 116. The nontransparent electrode 152 can be at least partly integrated into a wall of the housing 116. The nontransparent electrode 152 can be at least partly produced from high-grade steel, in particular as a high-grade steel plate 141. As already indicated, the nontransparent electrode 152 can comprise at least one metallic segment 128 of the housing 116.

[0151] The cell 110 can furthermore comprise at least one vacuum cell 154. The housing 116 and the electrodes 118 can be introduced into the vacuum cell 154. In other words, the vacuum cell 154 can enclose the housing 116 and the electrodes 118, as illustrated in FIG. 2, for example. The optical window 130 can be at least partly fixed between the housing 116 and at least one inner wall 156 of the vacuum cell. The optical window 130 can be at least partly accommodated in at least one mount 158. The mount 158 can be pressed against the inner wall 156 of the vacuum cell 154 by at least one spring element 160 mounted on the housing 116, for example a compression spring. The spring element 160 can be configured to contact the transparent electrically conductive coating 136. The mount 158 can comprise the holding unit 144 or at least parts of the holding unit 144, in particular the clamping mount 146. The vacuum cell 154 can be at least partly embodied as a transparent vacuum cell 154, in particular as a glass cell 162. The cell 110 can furthermore comprise at least one rod mechanism 164 for holding the housing 116 and the electrodes 118, in particular in the vacuum cell 154. The rod mechanism 164 can consist of at least one metal. The cell 110 can comprise electrode leads 166 for electrically contacting the electrodes 118. The electrode leads 166 can be at least partly integrated into the rod mechanism 164.

[0152] FIG. 4 shows a perspective illustration of a further exemplary embodiment of the cell 110 according to the invention for carrying out quantum optical measurements on at least one atom cloud. For the description of FIG. 4, recourse can be had extensively to the description of FIGS. 1 to 3.

[0153] In the case of the exemplary embodiment of the cell 110 as shown in FIG. 4, two in comparison large optical windows 130 are provided on the top side and the underside of the cell 110, through which a plurality of light beams 132 can be incident in the interior 120. Even light beams 168 with a high numerical aperture can be radiated in through these optical windows 130. In FIG. 4, the atom cloud is situated centrally in the interior 120 of the cell 110, this once again being indicated by the reference sign 112.

[0154] FIG. 5 shows one exemplary embodiment of a facility for contacting electrodes 118 of the exemplary embodiment of the cell 110 according to the invention in accordance with FIG. 4, which however is also analogously applicable to the exemplary embodiment in FIGS. 1-3. The cell 110 can generally comprise at least two electrical terminals 170 for connection to at least one voltage source 172. The electrical terminals 170 can be electrically connected to the electrodes 118, for example via cable connections 174. As already indicated, the cell 110 can have a high-vacuum region 176. The housing 116 and the electrodes 118 can be arranged in the high-vacuum region 176. The electrical terminals 170 can be arranged outside the high-vacuum region 176, for example on a high-vacuum bushing 178. Cable connections 180 compatible with high vacuum can be used in the high-vacuum region, which connections can be provided with Kapton insulations, for example. The cable connections 180 can be led or integrated for example wholly or partly in a connection piece, such as the connection piece 124 shown above, for example, and/or in a carrier construction, such as the carrier construction 126 shown above, for example.

[0155] FIG. 6 shows a schematic illustration of one exemplary embodiment of a system 182 according to the invention for carrying out quantum optical measurements on at least one atom cloud. The system 182 comprises at least one cell 110 according to any of the preceding or below-described embodiments. The system 182 furthermore comprises at least one adjustable voltage source 172. The voltage source 172 is connected to the electrodes 118. The at least one electric field in the interior 120 of the housing 116 is adjustable, in particular controllable, by means of the voltage source 172. The system 182 can furthermore comprise at least one electrical coil 184 for generating at least one magnetic field in the interior 120. The electrical coil 184 can be connected to at least one current source 185. In particular, the electrical coil 184 can comprise a Helmholtz coil 186. In this regard, a pair of Helmholtz coils 186 arranged around the cell 110 can be used, for example.

[0156] The system 182 can furthermore comprise at least one light source 188 for generating the at least one light beam 132, in particular at least one laser source 190. The light source 188 can be arranged in such a way that the light beam 132 is able to be radiated into the interior 120 through the at least one optical window 130 for interaction with the atom cloud. The light beam 132 can function in particular as optical tweezers and/or as a gate laser.

[0157] The system 182 can furthermore comprise at least one optical system 192. The optical system 192 can be configured to radiate the light beam 132 with a numerical aperture of at least 0.1 through the optical window 130 into the interior 120. The optical system 192 can comprise in particular at least one microscope objective 194. The system 182 can furthermore comprise at least one atom source 196 connected to the cell 110. The atom source 196 can be configured to introduce atoms, molecules or ions of the atom cloud into the interior 120. In particular, the atom source 196 can be configured as heatable, e.g. in an effusion cell. As shown in FIG. 6, the vacuum cell 154 can have at least one flange 198 for connection to a high-vacuum device 200, in particular a high-vacuum device 200 with at least one vacuum pump 202, for example a turbo pump, an ion pump, a titanium sublimation pump and/or a non-evaporable getter (NEG) pump.

[0158] FIG. 7 shows a schematic illustration of one exemplary embodiment of a quantum computer 204 according to the invention. The quantum computer 204 comprises at least one system 182 according to any of the embodiments relating to a system 182 as described above or below. The quantum computer 204 furthermore comprises at least one controller unit 206 for addressing and/or reading out quantum bits in an atom cloud in the interior 120. The quantum computer 204 can furthermore comprise at least one interface 208 configured to enable communication between controller unit 206 and system 182. In addition, the interface 208 can be configured to enable communication with external apparatuses.

[0159] FIG. 8 shows a flow diagram of one exemplary embodiment of a method according to the invention for carrying out quantum optical measurements on at least one atom cloud. The method comprises the following steps: [0160] i. (identified by reference 210) providing at least one system 182 according to any of the embodiments relating to a system as described above or below; [0161] ii. (identified by reference sign 212) generating at least one high vacuum, in particular an ultrahigh vacuum, at the location of the cell 110 of the system 182, in particular in the interior 120; [0162] iii. (identified by reference sign 214) introducing at least one atom cloud into the interior 120 of the cell 110; [0163] iv. (identified by reference sign 216) radiating at least one light beam 132 through the at least one optical window 130 of the cell 110, such that the light beam 132 interacts with the atom cloud in the interior 120 of the cell 110; and [0164] v. (identified by reference sign 218) subjecting the electrodes 118 of the cell 110 to electrical potentials and adjusting an electric field in the interior 120 by means of the electrodes 118.

[0165] In this case, the method steps can be carried out in the indicated order or in a different order, wherein one or more of the method steps can at least partly also be carried out simultaneously and wherein one or more of the method steps can be repeated a number of times. Moreover, further method steps, independently of whether or not they are mentioned here, can be implemented in addition.

LIST OF REFERENCE SIGNS

[0166] 110 cell [0167] 112 location of the atom cloud [0168] 114 control unit [0169] 116 housing [0170] 118 electrode [0171] 120 interior [0172] 122 opening of the housing for introducing the atoms [0173] 124 connection piece [0174] 125 tunnel [0175] 126 carrier construction [0176] 128 metallic segment [0177] 130 optical window [0178] 132 light beam [0179] 134 substrate [0180] 136 electrically conductive coating [0181] 138 metallic plate [0182] 140 opening of the metallic plate [0183] 141 high-grade steel plate [0184] 142 opening of the housing for radiating in the light beam [0185] 144 holding unit [0186] 146 clamping mount [0187] 148 connection element [0188] 150 connection pin [0189] 152 nontransparent electrode [0190] 154 vacuum cell [0191] 156 inner wall of the vacuum cell [0192] 158 mount [0193] 160 spring element [0194] 162 glass cell [0195] 164 rod mechanism [0196] 166 electrode leads [0197] 168 light beam with high numerical aperture [0198] 170 electrical terminal [0199] 172 voltage source [0200] 174 cable connection [0201] 176 high-vacuum region [0202] 178 high-vacuum bushing [0203] 180 cable connection compatible with high vacuum [0204] 182 system [0205] 184 electrical coil [0206] 185 current source [0207] 186 Helmholtz coil [0208] 188 light source [0209] 190 laser source [0210] 192 optical system [0211] 194 microscope objective [0212] 196 atom source [0213] 198 flange [0214] 200 high-vacuum device [0215] 202 vacuum pump [0216] 204 quantum computer [0217] 206 controller unit [0218] 208 interface [0219] 210 method step i. [0220] 212 method step ii. [0221] 214 method step iii. [0222] 216 method step iv. [0223] 218 method step v.