Conversion from Single Photon to Single Electron Spin Using Electrically Controllable Quantum Dots

Consequences of Spin-Orbit Coupling at the Single Hole Level: Spin-Flip Tunneling and the Anisotropic g Factor

“…Interest in quantum networks [1] and long-distance quantum cryptography [2,3] led to proposals towards interfacing the photonic and solid-state spin qubits in gated lateral quantum dot devices [4,5]. Such an interface is a central element in quantum sensors and quantum repeaters [6,7], but could also be used to simplify the layout of multi-qubit gated devices [8].…”

“…An intermediate step in the transfer of the photon polarization state onto the state of the spin involves generation of an electron-hole pair. Therefore, beside long spin coherence time, the existing proposals [4,6,7] call for optical access (direct bandgap material) and engineering near-zero effective g-factor for the electron or the hole. While g * = 0 is desired, in practice it should be small enough for the resulting Zeeman splitting to be smaller than the photon bandwidth [6,7].…”

“…Currently the longest spin coherence times have been demonstrated for electron spin qubits in 28 Si [9], but their coupling to light is challenging due to the indirect bandgap. GaAs electronic devices, while more promising [4,5], still require g-factor engineering.…”

Phonon spectral density in a GaAs/AlGaAs double quantum dot

“…Charge and spin states in single and double quantum dots (DQDs) are candidates for quantum bits [1,2]. DQDs are being tested as coherent single-photon emitters [3][4][5] as well as for their applicability as photon to electron spin converters [6]. All of these experiments suffer from relaxation and dephasing of quantum states due to their interaction with the environment.…”

Review of performance metrics of spin qubits in gated semiconducting nanostructures

“…The reader interested in these aspects can consult, for example, Refs. [35,75,79,123,132,193,195,219,224,225,236,248,253].…”