Abstract
An electronic component (10, 110) is designed as a semiconductor or with a semiconductor-like structure for moving a quantum dot (68, 168) over a distance. The electronic component (10, 110) comprises a substrate (32, 132) having a two-dimensional electron gas or electron hole gas. A gate electrode assembly (16, 18, 20, 116, 118, 120) having gate electrodes (38, 40, 42, 44, 138, 140, 142, 144) is arranged on a surface (31, 131) of the electronic component (10, 110). The gate electrode assembly (16, 18, 20, 116, 118, 120) produces a potential well (66, 166) in the substrate (32, 132). Electrical terminals for connecting the gate electrode assembly (16, 18, 20, 116, 118, 120) to voltage sources are provided for this purpose. The disclosure further relates to a method for such an electronic component (10, 110).
Claims
1-8. (canceled)
9. An electronic component (10, 110), which is designed as a semiconductor or with a semiconductor-like structure for moving a quantum dot (68, 168) over a distance, comprising: a substrate (32, 132) with a two-dimensional electron gas or electron hole gas; a gate electrode assembly (16, 18, 20, 116, 118, 120) having gate electrodes (38, 40, 42, 44, 138, 140, 142, 144), which is arranged on a surface (31, 131) of the electronic component (10, 110), for producing a potential well (66, 166) in the substrate (32, 132); and electrical terminals for connecting the gate electrode assembly (16, 18, 20, 116, 118, 120) to voltage sources, wherein the gate electrodes (38, 40, 42, 44, 138, 140, 142, 144) have parallel electrode fingers (46, 48, 50, 52, 146, 148, 150, 152), and wherein the parallel electrode fingers (46, 48, 50, 52, 146, 148, 150, 152) are interconnected in a periodically alternating manner, which causes an almost continuous movement of the potential well (66, 166) through the substrate (32, 132), whereby a quantum dot (68, 168) is transported with this potential well (66, 166).
10. The electronic component (10, 110) according to claim 9, wherein the gate electrodes (38, 40, 42, 44, 138, 140, 142, 144) are two parallel, gate electrodes (33, 34, 133, 134) which form a channel-like structure (36, 136).
11. The electronic component (10, 110) according to one of claim 9, wherein the substrate (32, 132) of the electronic component (10, 110) comprises gallium arsenide (GaAs) and/or silicon germanium (SiGe).
12. The electronic component (10, 110) according to claim 9, wherein the gate electrodes (38, 40, 42, 44, 138, 140, 142, 144) are connected to each other and configured such that a periodic and/or phase-shifted voltage can be applied to them.
13. The electronic component (10, 110) according to claim 9, wherein every third of the parallel electrode fingers (46, 48, 50, 52, 146, 148, 150, 152) is connected to one of the gate electrodes (38, 40, 42, 44, 138, 140, 142, 144).
14. The electronic component (10, 110) according to claim 9, further comprising means for connecting two qubits (12, 14, 112, 114) of a quantum computer.
15. A method for the electronic component (10, 110) according to claim 9, comprising: applying a phase-shifted voltage to the gate electrodes (38, 40, 42, 44, 138, 140, 142, 144), thereby causing an almost continuous movement of the potential well (66, 166) through the substrate (32, 132), and thereby transporting the quantum dot (68, 168) with the potential well (66, 166).
16. The method according to claim 15, wherein every fourth of the gate electrodes (38, 40, 42, 44, 138, 140, 142, 144) is connected to one other and to which a periodic voltage is applied.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 shows the schematic top view of an electronic component made of GaAs, which is arranged between two qubits.
[0028] FIG. 2 shows a top view of a first layer of the gate electrode assembly according to FIG. 1.
[0029] FIG. 3 shows a top view of a second layer of the gate electrode assembly according to FIG. 1.
[0030] FIG. 4 shows a top view of a third layer of the gate electrode assembly according to FIG. 1.
[0031] FIG. 5 shows a schematic diagram of a cross-section through the second layer of the gate electrode assembly according to FIG. 1.
[0032] FIG. 6 shows a schematic diagram of a cross-section through the third layer of the gate electrode assembly according to FIG. 1.
[0033] FIG. 7 shows a schematic top view of the structure of the electronic component according to FIG. 1 for a single period.
[0034] FIG. 8 shows a longitudinal section according to FIG. 1 through the electronic component.
[0035] FIG. 9 shows the schematic top view of an electronic component made of SiGe, which is arranged between two qubits.
[0036] FIG. 10 shows a top view of a first layer of the gate electrode assembly according to FIG. 9.
[0037] FIG. 11 shows a top view of a second layer of the gate electrode assembly according to FIG. 9.
[0038] FIG. 12 shows a top view of a third layer of the gate electrode assembly according to FIG. 9.
[0039] FIG. 13 shows a schematic diagram of a cross-section through the second layer of the gate electrode assembly according to FIG. 9.
[0040] FIG. 14 shows a schematic diagram of a cross-section through the third layer of the gate electrode assembly according to FIG. 9.
[0041] FIG. 15 shows a longitudinal section according to FIG. 9 through the electronic component.
DETAILED DESCRIPTION
[0042] FIG. 1 shows a first exemplary embodiment of an electronic component 10 or component based on gallium arsenide (GaAs). The electronic component 10 is shown schematically in a top view. The structures of the component are preferably nanoscale structures. The electronic component 10 couples two qubits 12, 14 to one another. In the present exemplary embodiment, the electronic component 10 comprises three layers of gate electrode assemblies 16, 18, 20, which are separated from one another by insulating layers 22, 24. The gate electrode assemblies 16, 18, 20 are supplied with a suitable voltage via electrical connections 26, 28, 30.
[0043] The first and lowermost gate electrode assembly 16 rests on a flat outer surface 31 of a substrate 32. In the present exemplary embodiment, the substrate 32 is comprised of doped gallium arsenide (GaAs). The layer of the first gate electrode assembly 16 is followed by the insulating layer 22, on which the second gate electrode assembly 18 is provided. The insulating layer 24, which electrically isolates the second gate electrode assembly 18 from the third and uppermost gate electrode assembly 20, lies on the second gate electrode assembly 18.
[0044] In FIG. 2 according to FIG. 1, the arrangement of the first gate electrode assembly 16, which connects the qubits 12, 14 to one another, is shown schematically. This gate electrode assembly 16 comprises two parallel gate electrodes 33, 34, which have the first electrical connections 26 for the supply voltage. The gate electrodes 33, 34 form a channel-like structure 36.
[0045] FIGS. 3 and 4 according to FIG. 1 show a schematic of the second and third gate electrode assemblies 18, 20, each of which comprises two gate electrodes 38, 40 and 42, 44, respectively, arranged in parallel. Each of these gate electrodes 38, 40, 42, 44 has an electrical connection 28, 30 for the supply voltage. These gate electrodes 38, 40, 42, 44 are finger-shaped with electrode fingers 46, 48, 50, 52. The electrode fingers 46, 48, 50, 52, which are spaced apart, engage one another in a plane 54, 56 of the gate electrode assemblies 18, 20 without touching one another. The gate electrode assemblies 18, 20 are arranged offset to one another in a suitable manner so that the electrode fingers 46, 48, 50, 52 are shifted with respect to each other in an alternating manner in the top view.
[0046] In FIGS. 5 and 6 according to FIG. 1, a cross section of the electronic component 10 is shown schematically. FIG. 5 shows a section A-A according to FIG. 7 through the second layer, and FIG. 6 shows a section B-B according to FIG. 7 through the third layer. The gate electrode assemblies 16, 18, 20 and the insulating layers 22, 24 are arranged above the substrate 32.
[0047] In section A-A in FIG. 5, the channel-like structure 36 of the first gate electrode assembly 16, which rests directly on the substrate 32, is clearly visible. For this purpose, the two gate electrodes 33, 34 are arranged in parallel with a channel-like structure 36. The first insulating layer 22 is provided over the gate electrodes 33, 34. The second gate electrode assembly 18 is located on this insulating layer 22. One electrode finger 46 of the gate electrode 38 of the second gate electrode assembly 18 is visible on the first insulating layer 22 in this diagram of the sectional area. In the sectional diagram, one connection 58 for the electrode finger 48 of gate electrode 40 of the second gate electrode assembly 18 is visible (FIG. 3). The second insulating layer 24, on which the third gate electrode assembly 20 is arranged, is provided over the second gate electrode assembly 18. In the section shown, only one connection 60, 62 of each of the gate electrodes 42, 44 of the third gate electrode assembly 20 is visible between the electrode fingers 50, 52 (FIG. 4).
[0048] Analogous to FIG. 5, the channel-like structure 36 of the first gate electrode assembly 16 is also visible in section B-B in FIG. 6, which extends unchanged along the entire electronic component 10 (see FIG. 1). In FIG. 6, the first gate electrode assembly 16 lies on the substrate 32. The first insulating layer 22 is located above the gate electrodes 33, 34 of the gate electrode assembly 16. The second gate electrode assembly 18 is located on this insulating layer 22. In the section shown, only one connection 58, 64 of each of the gate electrodes 38, 40 of the second gate electrode assembly 18 is visible between the electrode fingers 46, 48 (FIG. 3). The second insulating layer 24, on which the third gate electrode assembly 20 is arranged, is provided over the second gate electrode assembly 18. One electrode finger 50 of the gate electrode 42 of the third gate electrode assembly 20 is visible on the second insulating layer 24 in this diagram of the sectional area. Only the connection 62 of the gate electrode 44 of the third gate electrode assembly 20 is visible here.
[0049] FIG. 7 is shown according to FIG. 1 in a schematic top view of the electronic component 10 as an enlarged section for a single period. The channel-like structure 36 of the first gate electrode assembly 16 is shown as the lowest layer. As described above, the second and third gate electrode assemblies 18, 20, which are insulated from one another, are located above this. The electrode fingers 46, 48 of the gate electrodes 38, 40 of the second gate electrode assembly 18 engage in one another without contact in the plane 54. The electrode fingers 50, 52 of the gate electrodes 42, 44 of the third gate electrode assembly 20 engage in one another without contact in the plane 56. The gate electrodes 38, 40 and 42, 44 are arranged such that the electrode fingers 46, 48, 50, 52 alternate.
[0050] FIG. 8 shows, as a section of the electronic component 10, a longitudinal section C-C according to FIG. 7. The two-dimensional electron gas (2DEG) is formed in the substrate 32 of the electronic component 10. In this cross-sectional view, the gate electrode 33 of the first gate electrode assembly 16 is visible. The gate electrode 33 extends longitudinally directly on the outer surface 31 of the substrate 32 and is separated from the second gate electrode assembly 18 by the first insulating layer 22. The transverse electrode fingers 46, 48 of the second gate electrodes 38, 40 can be seen in section. The second gate electrode assembly 18 is separated from the third gate electrode assembly 20 by the second insulating layer 24. Of the third gate electrode assembly 20, only the electrode fingers 50, 52 of the gate electrodes 42, 44 can be seen. In this section, it becomes clear how the electrode fingers 46, 48, 50, 52 alternate. By suitably applying sinusoidal voltages to the gate electrode assemblies 16, 18, 20, a potential well 66 is generated. A quantum dot 68 trapped in this potential well 66 can be transported through the substrate. The potential well 66 is transported longitudinally through the substrate through suitable control of the electrode fingers 46, 48, 50, 52 with sinusoidal voltages, without the quantum dot 68 changing its quantum mechanical properties. The movement of the quantum dot 68 in the direction of the arrow 70 is indicated by a dashed line 72. The quantum mechanical state is represented symbolically by the small arrow 74 of the quantum dot 68.
[0051] Voltage is applied to the gate electrode assemblies 16, 18, 20 such that the electrode fingers 46, 48, 50, 52 of the gate electrodes 38, 40 and 42, 44 form the movable potential well 66 in the substrate 32 of the electronic component 10. Through suitable control of the gate electrode assemblies 16, 18, 20, the potential well 66 can be guided in a controlled manner along the channel-like structure 36 through the substrate 32. In the present exemplary embodiment, the gate electrodes 38, 40 and 42, 44 of the second and third gate electrode assemblies 18, 20 have a sinusoidal voltage profile applied to them, which is suitably phase-shifted between the gate electrodes 38, 40, 42, 44. The quantum dot 68, which is confined in this potential well 66, can be transported with this potential well 66 over a distance in the two-dimensional electron gas of the substrate 32 made of GaAs from one qubit 12 to the other qubit 14 without experiencing a quantum mechanical change of state.
[0052] FIG. 9 shows a second exemplary embodiment for an electronic component 110 based on undoped silicon germanium (SiGe). Due to the opposite polarity with respect to the previous exemplary embodiment with doped GaAs required for this, a slightly different structure of the electronic component is required.
[0053] The electronic component 110 is shown schematically in a top view. The electronic component 110 couples two qubits 112, 114 to one another. In the present exemplary embodiment, the electronic component 110 comprises three layers of gate electrode assemblies 116, 118, 120, which are separated from one another by insulating layers 122, 124. The gate electrode assemblies 116, 118, 120 are supplied with a suitable voltage via electrical connections 126, 128, 130.
[0054] The first and lowermost gate electrode assembly 116 rests on a flat surface 131 of a substrate 132. In the present exemplary embodiment, the substrate 132 consists of silicon germanium (SiGe). The layer of the first gate electrode assembly 116 is followed by the insulating layer 122, on which the second gate electrode assembly 118 is provided. The insulating layer 124, which electrically isolates the second gate electrode assembly 118 from the third and uppermost gate electrode assembly 120, lies on the second gate electrode assembly 118.
[0055] FIG. 10 schematically shows the arrangement of the first gate electrode assembly 116, which connects the qubits 112, 114 to one another. This gate electrode assembly 116 comprises two parallel gate electrodes 133, 134, which have the first electrical connections 126 for the supply voltage. The gate electrodes 133, 134 form a channel-like structure 136.
[0056] FIGS. 11 and 12 schematically show the second and third gate electrode assemblies 118, 120, each of which comprises two gate electrodes 138, 140 and 142, 144, respectively, arranged in parallel. Each of these gate electrodes 138, 140, 142, 144 has an electrical connection 128, 130 for the supply voltage. These gate electrodes 138, 140, 142, 144 are finger-shaped with electrode fingers 146, 148, 150, 152. The electrode fingers 146, 148, 150, 152, which are spaced apart, engage one another in a plane 154, 156 of the gate electrode assemblies 118, 120 without touching one another. The gate electrode assemblies 118, 120 are arranged offset to one another in a suitable manner so that the electrode fingers 146, 148, 150, 152 are shifted with respect to each other in an alternating manner in the top view.
[0057] FIGS. 13 and 14 each schematically show a cross-section of the electronic component 110. FIG. 13 shows a section through the electrode finger 146 of the second layer, and FIG. 14 shows a section through the electrode finger 150 of the third layer. The gate electrode assemblies 116, 118, 120 and the insulating layers 122, 124 are arranged above the substrate 132.
[0058] In FIG. 13, the channel-like structure 136 of the first gate electrode assembly 116, which rests directly on the substrate 132, becomes clear. The channel-like structure 136 is formed significantly narrower than in the first exemplary embodiment according to FIG. 1-8. For this purpose, the two gate electrodes 133, 134 are arranged in parallel with a channel-like structure 136. The first insulating layer 122 is provided over the gate electrodes 133, 134. The second gate electrode assembly 118 is located on this insulating layer 122. One electrode finger 146 of the gate electrode 138 of the second gate electrode assembly 118 is visible on the first insulating layer 122 in this diagram of the sectional area. In the sectional diagram, one connection 158 for the electrode finger 148 of gate electrode 140 of the second gate electrode assembly 118 is visible. The second insulating layer 124, on which the third gate electrode assembly 120 is arranged, is provided over the second gate electrode assembly 118. In the section shown, only one connection 160, 162 of each of the gate electrodes 142, 144 of the third gate electrode assembly 120 is visible between the electrode fingers 150, 152.
[0059] Analogous to FIG. 13, the channel-like structure 136 of the first gate electrode assembly 116 is also visible in the section of FIG. 14, which extends unchanged along the entire electronic component 110 (see FIG. 9). In FIG. 13, the first gate electrode assembly 116 lies on the substrate 132. The first insulating layer 122 is located above the gate electrodes 133, 134 of the gate electrode assembly 116. The second gate electrode assembly 118 is located on this insulating layer 122. In the section shown, only the connection 158, 164 of each of the gate electrodes 138, 140 of the second gate electrode assembly 118 is visible between the electrode fingers 146, 148. The second insulating layer 124, on which the third gate electrode assembly 120 is arranged, is provided over the second gate electrode assembly 118. One electrode finger 150 of the gate electrode 142 of the third gate electrode assembly 120 is visible on the second insulating layer 124 in this diagram of the sectional area. Only the connection 162 of the gate electrode 144 of the third gate electrode assembly 120 is visible here.
[0060] FIG. 15 shows, as a section of the electronic component 110, a longitudinal section, the plane of which is situated between the channel-like structure 136. The two-dimensional electron gas (2DEG) is formed in the substrate 132 of the electronic component 110. In this cross-sectional view, the gate electrode 133 of the first gate electrode assembly 116 is visible. The gate electrode 133 extends longitudinally directly on the outer surface 131 of the substrate 132 and is separated from the second gate electrode assembly 118 by the first insulating layer 122.
[0061] The transverse electrode fingers 146, 148 of the second gate electrodes 138, 140 can be seen in section. The second gate electrode assembly 118 is separated from the third gate electrode assembly 120 by the second insulating layer 124. Of the third gate electrode assembly 120, only the electrode fingers 150, 152 of the gate electrodes 142, 144 can be seen. In this section, it becomes clear how the electrode fingers 146, 148, 150, 152 alternate. By suitably applying voltages to the gate electrode assemblies 116, 118, 120, a potential well 166 is generated. A quantum dot 168 trapped in this potential well 166 can be transported through the substrate. The potential well 166 is transported longitudinally through the substrate through suitable control of the electrode fingers 146, 148, 150, 152 with voltages, without the quantum dot 168 changing its quantum mechanical properties.
[0062] Voltage is applied to the gate electrode assemblies 116, 118, 120 such that the electrode fingers 146, 148, 150, 152 of the gate electrodes 138, 140 and 142, 144 form the movable potential well 166 in the substrate 132 of the electronic component 110. Through suitable control of the gate electrode assemblies 116, 118, 120, the potential well 166 can be guided in a controlled manner along the channel-like structure 136 through the substrate 132. In the present exemplary embodiment, the gate electrodes 138, 140 and 142, 144 of the second and third gate electrode assemblies 118, 120 have a sinusoidal voltage profile applied to them, which is suitably phase-shifted between the gate electrodes 138, 140, 142, 144. The quantum dot 168, which is confined in this potential well 166, can be transported with this potential well 166 over a distance in the two-dimensional electron gas of the substrate 132 made of SiGe from one qubit 112 to the other qubit 114 without experiencing a quantum mechanical change of state. The movement of the quantum dot 168 in the direction of the arrow 170 is indicated by a dashed line 172. The quantum mechanical state is represented symbolically by the small arrow 174 of the quantum dot 168.
[0063] It should be noted that instead of an electron, as in the previous exemplary embodiments, which forms the quantum dot 68 with a defined quantum mechanical state, holes can also be considered quantum dots in which an electron is correspondingly missing.
LIST OF REFERENCE SIGNS
[0064] 10 Electronic component [0065] 12, 14 Qubit [0066] 16 First gate electrode assembly [0067] 18 Second gate electrode assembly [0068] 20 Third gate electrode assembly [0069] 22 First insulating layer [0070] 24 Second insulating layer [0071] 26, 28, 30 Electrical connections [0072] 31 Outer surface of the substrate [0073] 32 Substrate (GaAs) [0074] 33, 34 Gate electrode (1st layer) [0075] 36 Channel-like structure [0076] 38, 40 Gate electrode (2nd layer) [0077] 42, 44 Gate electrode (3rd layer) [0078] 46, 48 Electrode finger (2nd layer) [0079] 50, 52 Electrode finger (3rd layer) [0080] 54, 56 Plane (first gate electrode assembly) [0081] 58 Connection (2nd layer) [0082] 60, 62 Connection (3rd layer) [0083] 64 Connection (2nd layer) [0084] 66 Potential well [0085] 68 Quantum dot (electron) [0086] 70 Direction of arrow [0087] 72 Dashed lines (potential well) [0088] 74 Arrow [0089] 110 Electronic component [0090] 112, 114 Qubit [0091] 116 First gate electrode assembly [0092] 118 Second gate electrode assembly [0093] 120 Third gate electrode assembly [0094] 122 First insulating layer [0095] 124 Second insulating layer [0096] 126, 128, 130 Electrical connections [0097] 131 Outer surface of the substrate [0098] 132 Substrate (SiGe) [0099] 133, 134 Gate electrode (1st layer) [0100] 136 Channel-like structure [0101] 138, 140 Gate electrode (2nd layer) [0102] 142, 144 Gate electrode (3rd layer) [0103] 146, 148 Electrode finger (2nd layer) [0104] 150, 152 Electrode finger (3rd layer) [0105] 154, 156 Plane (first gate electrode assembly) [0106] 158 Connection (2nd layer) [0107] 160, 162 Connection (3rd layer) [0108] 164 Connection (2nd layer) [0109] 166 Potential well [0110] 168 Quantum dot (hole) [0111] 170 Direction of arrow [0112] 172 Dashed lines (potential well) [0113] 174 Arrow
