Enhanced readout of spin states in double quantum dot
| Autor: | Hai-Ou Li, Ming Xiao, Bao-Chuan Wang, Bao-Bao Chen, Guo-Ping Guo, Gang Cao |
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| Rok vydání: | 2017 |
| Předmět: |
Physics
Multidisciplinary Condensed matter physics Spin polarization Spin states Diradical 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Quantum dot Qubit 0103 physical sciences Singlet state Triplet state 010306 general physics 0210 nano-technology Spin-½ |
| Zdroj: | Science Bulletin. 62:712-716 |
| ISSN: | 2095-9273 |
| DOI: | 10.1016/j.scib.2017.04.024 |
| Popis: | We investigate a spin-to-charge conversion mechanism which maps the spin singlet and triplet states to two charge states differing by one electron mediated by an intermediate metastable charge state. This mechanism allows us to observe fringes in the spin-unblocked region beyond the triplet transition line in the measurement of the exchange oscillations between singlet and triplet states in a four-electron double quantum dot. Moreover, these fringes are amplified and π π -phase shifted, compared with those in the spin blockade region. Unlike the signal enhancement mechanism reported before which produces similar effects, this mechanism only requires one dot coupling to the lead, which is a commonly encountered case especially in imperfect devices. Besides, the crucial tunnel rate asymmetry is provided by the dependence on spin state, not by the asymmetric couplings to the leads. We also design a scheme to control the amplification process, which enables us to extract the relevant time parameters. This mechanism will have potential applications in future investigations of spin qubits. |
| Databáze: | OpenAIRE |
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