Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain
Heisenberg exchange coupling between neighboring electron spins in semiconductor quantum dots provides a powerful tool for quantum information processing and simulation. Although so far unrealized, extended Heisenberg spin chains can enable long-distance quantum information transfer and the generati...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-07-01
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| Series: | Physical Review X |
| Online Access: | http://doi.org/10.1103/PhysRevX.10.031006 |
| _version_ | 1818741234684919808 |
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| author | Haifeng Qiao Yadav P. Kandel Kuangyin Deng Saeed Fallahi Geoffrey C. Gardner Michael J. Manfra Edwin Barnes John M. Nichol |
| author_facet | Haifeng Qiao Yadav P. Kandel Kuangyin Deng Saeed Fallahi Geoffrey C. Gardner Michael J. Manfra Edwin Barnes John M. Nichol |
| author_sort | Haifeng Qiao |
| collection | DOAJ |
| description | Heisenberg exchange coupling between neighboring electron spins in semiconductor quantum dots provides a powerful tool for quantum information processing and simulation. Although so far unrealized, extended Heisenberg spin chains can enable long-distance quantum information transfer and the generation of nonequilibrium quantum states. In this work, we implement simultaneous, coherent exchange coupling between all nearest-neighbor pairs of spins in a quadruple quantum dot. The main challenge in implementing simultaneous exchange couplings is the nonlinear and nonlocal dependence of the exchange couplings on gate voltages. Through a combination of electrostatic simulation and theoretical modeling, we show that this challenge arises primarily due to lateral shifts of the quantum dots during gate pulses. Building on this insight, we develop two models that can be used to predict the confinement gate voltages for a desired set of exchange couplings. Although the model parameters depend on the number of exchange couplings desired (suggesting that effects in addition to lateral wave-function shifts are important), the models are sufficient to enable simultaneous and independent control of all three exchange couplings in a quadruple quantum dot. We demonstrate two-, three-, and four-spin exchange oscillations, and our data agree with simulations. |
| first_indexed | 2024-12-18T01:53:23Z |
| format | Article |
| id | doaj.art-7babeef54e764395b212bf39590a69b3 |
| institution | Directory Open Access Journal |
| issn | 2160-3308 |
| language | English |
| last_indexed | 2024-12-18T01:53:23Z |
| publishDate | 2020-07-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review X |
| spelling | doaj.art-7babeef54e764395b212bf39590a69b32022-12-21T21:24:58ZengAmerican Physical SocietyPhysical Review X2160-33082020-07-0110303100610.1103/PhysRevX.10.031006Coherent Multispin Exchange Coupling in a Quantum-Dot Spin ChainHaifeng QiaoYadav P. KandelKuangyin DengSaeed FallahiGeoffrey C. GardnerMichael J. ManfraEdwin BarnesJohn M. NicholHeisenberg exchange coupling between neighboring electron spins in semiconductor quantum dots provides a powerful tool for quantum information processing and simulation. Although so far unrealized, extended Heisenberg spin chains can enable long-distance quantum information transfer and the generation of nonequilibrium quantum states. In this work, we implement simultaneous, coherent exchange coupling between all nearest-neighbor pairs of spins in a quadruple quantum dot. The main challenge in implementing simultaneous exchange couplings is the nonlinear and nonlocal dependence of the exchange couplings on gate voltages. Through a combination of electrostatic simulation and theoretical modeling, we show that this challenge arises primarily due to lateral shifts of the quantum dots during gate pulses. Building on this insight, we develop two models that can be used to predict the confinement gate voltages for a desired set of exchange couplings. Although the model parameters depend on the number of exchange couplings desired (suggesting that effects in addition to lateral wave-function shifts are important), the models are sufficient to enable simultaneous and independent control of all three exchange couplings in a quadruple quantum dot. We demonstrate two-, three-, and four-spin exchange oscillations, and our data agree with simulations.http://doi.org/10.1103/PhysRevX.10.031006 |
| spellingShingle | Haifeng Qiao Yadav P. Kandel Kuangyin Deng Saeed Fallahi Geoffrey C. Gardner Michael J. Manfra Edwin Barnes John M. Nichol Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain Physical Review X |
| title | Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain |
| title_full | Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain |
| title_fullStr | Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain |
| title_full_unstemmed | Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain |
| title_short | Coherent Multispin Exchange Coupling in a Quantum-Dot Spin Chain |
| title_sort | coherent multispin exchange coupling in a quantum dot spin chain |
| url | http://doi.org/10.1103/PhysRevX.10.031006 |
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