Precise measurements of the dipole moment and polarizability of the neutral exciton and positive trion in a single quantum dot

We report a high-resolution photocurrent (PC) spectroscopy of a single self-assembled InAs/GaAs quantum dot (QD) embedded in an n-i-Schottky device with an applied vector magnetic field. The PC spectra of positively charged exciton (X +) and neutral exciton (X 0) are obtained by two-color resonant excitation. With an applied magnetic field in Voigt geometry, the double Λ energy level structure of X + and the dark states of X 0 are observed in PC spectra clearly. In Faraday geometry, the PC amplitude of X + decreases and then quenches with the increasing of the magnetic field, which provides a new way to determine the relative sign of the electron and the hole g-factors. With an applied vector magnetic field, the electron and the hole g-factor tensors of X + and X 0 are obtained. The anisotropy of the hole g-factors of both X + and X 0 is larger than that of the electron.

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“…Furthermore, the fitting parameters in Fig. 1(e) can also provide the dipole moment and polarizability of X 0 and X + precisely [47].…”

Section: Results and Disscussionmentioning

confidence: 99%

Electron and Hole g Tensors of Neutral and Charged Excitons in Single Quantum Dots by High-Resolution Photocurrent Spectroscopy

Peng

Xie

et al. 2020

Phys. Rev. Applied

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“…Finally, while QDs dots are often considered as polar due to the presence of a strong permanent excitonic dipole moment alone, it has been demonstrated that they possess a very high excited‐state polarizability, typically comparable to their volume, such that

χ / (ϵ_{0} V_{normalI}) \approx 1

. These two factors combined imply that the reaction field cannot be neglected, as is the case in the empty‐cavity model.…”

Section: The Onsager−böttcher Treatment Of a Dipole In A Cavitymentioning

confidence: 99%

Understanding Local‐Field Correction Factors in the Framework of the Onsager−Böttcher Model

2019

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The determination of the appropriate local-field factor for quantifying the response of a molecule to an external electric field is of major importance in optical spectroscopy. Although numerous studies have dealt with the evolution of the optical properties of emitters as a function of their environment, the choice of the model used to quantify local fields is still ambiguous, and sometimes even arbitrary. In this paper, we review the Onsager-Böttcher model, which introduces the polarizability of the probe molecule as the determinant parameter for the local field factor, and we establish a simple conceptual framework encompassing all commonly used models. Finally, a discussion of published experimental research illustrates the potential of the measurement of local electric fields in dense dielectric media, as well as the subtleties involved in their interpretation.

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“…However, the finite dephasing time of the carriers in QDs makes the qubit to be manipulated by ultrashort laser pulses, which limits the resolution because of the wide spectral linewidth. In contrast, continuous-wave (CW) laser owns ultra-narrow-bandwidth that allows high-resolution measurement [19,20] and high-fidelity initialization of the QD spin qubit [21] through PC spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Probing the Dark-Exciton States of a Single Quantum Dot Using Photocurrent Spectroscopy in a Magnetic Field

Peng

Tang

et al. 2017

Phys. Rev. Applied

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We report on high-resolution photoluminescence (PL) and photocurrent (PC) spectroscopies of a single self-assembled InAs/GaAs quantum dot (QD) embedded in an n-i-Schottky device with an applied magnetic field in Faraday and Voigt geometries. The single-QD PC spectrum of neutral exciton (X 0 ) is obtained by sweeping the bias-dependent X 0 transition energy to achieve resonance with a fixed narrow-bandwidth laser through quantum-confined Stark effect. With a magnetic field applied in Faraday geometry, the diamagnetic effect and the Zeeman splitting of X 0 are observed both in PL and PC spectra. When the magnetic field is applied in Voigt geometry, the mixture of bright and dark states results in an observation of dark exciton states, which are confirmed by the polarization-resolved PL and PC spectra.

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Precise measurements of the dipole moment and polarizability of the neutral exciton and positive trion in a single quantum dot

Cited by 15 publications

References 27 publications

Electron and Hole g Tensors of Neutral and Charged Excitons in Single Quantum Dots by High-Resolution Photocurrent Spectroscopy

Electron and Hole g Tensors of Neutral and Charged Excitons in Single Quantum Dots by High-Resolution Photocurrent Spectroscopy

Understanding Local‐Field Correction Factors in the Framework of the Onsager−Böttcher Model

Probing the Dark-Exciton States of a Single Quantum Dot Using Photocurrent Spectroscopy in a Magnetic Field

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