Quantum dot molecule devices with optical control of charge status and electronic control of coupling
| Autor: | Bopp, Frederik, Rojas, Jonathan, Revenga, Natalia, Riedl, Hubert, Sbresny, Friedrich, Boos, Katarina, Simmet, Tobias, Ahmadi, Arash, Gershoni, David, Kasprzak, Jacek, Ludwig, Arne, Reitzenstein, Stephan, Wieck, Andreas, Reuter, Dirk, Muller, Kai, Finley, Jonathan J. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Adv Quantum Technol. 2022, 5, 2200049 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1002/qute.202200049 |
| Popis: | Tunnel-coupled pairs of optically active quantum dots - quantum dot molecules (QDMs) - offer the possibility to combine excellent optical properties such as strong light-matter coupling with two-spin singlet-triplet ($S-T_0$) qubits having extended coherence times. The $S-T_0$ basis formed using two spins is inherently protected against electric and magnetic field noise. However, since a single gate voltage is typically used to stabilize the charge occupancy of the dots and control the inter-dot orbital couplings, operation of the $S-T_0$ qubits under optimal conditions remains challenging. Here, we present an electric field tunable QDM that can be optically charged with one (1h) or two holes (2h) on demand. We perform a four-phase optical and electric field control sequence that facilitates the sequential preparation of the 2h charge state and subsequently allows flexible control of the inter-dot coupling. Charges are loaded via optical pumping and electron tunnel ionization. We achieve one- and two-hole charging efficiencies of 93.5 $\pm$ 0.8 % and 80.5 $\pm$ 1.3 %, respectively. Combining efficient charge state preparation and precise setting of inter-dot coupling allows control of few-spin qubits, as would be required for on-demand generation of two-dimensional photonic cluster states or quantum transduction between microwaves and photons. Comment: 4 figures |
| Databáze: | arXiv |
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