Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1902.01979 · Physical review. B./Physical review. B

Spectroscopy of double quantum dot two-spin states by tuning the interdot barrier

G. Giavaras, Y. Tokura

Published Feb 8, 2019• 12 citations
arXivHTMLPDF

Abstract

Transport spectroscopy of two-spin states in a double quantum dot can be performed by an ac electric field which tunes the energy detuning. However, a problem arises when the transition rate between the states is small and, consequently, the ac-induced current is suppressed. Here we show that if the ac field tunes the interdot tunnel barrier, then for large detuning the transition rate increases drastically, resulting in high current. Multiphoton resonances are enhanced by orders of magnitude. Our study demonstrates an efficient way for fast two-spin transitions.

DOI
10.1103/physrevb.99.075412

Related papers

Microwave spectroscopy of spin–orbit coupled states: Energy detuning vs interdot coupling modulation

G. Giavaras, 康弘 都倉

We study the AC field induced current peaks of a spin-blockaded double quantum dot with spin–orbit interaction. The AC field modulates either the interdot tunnel coupling or the energy detuning, and we choose the AC field frequency range to induce two singlet–triplet transitions giving rise to two current peaks. We show that for a large detuning, the two current peaks can be significantly stronger when the AC field modulates the tunnel coupling, thus making the detection of the spin–orbit gap more efficient. We also demonstrate the importance of the time dependence of the spin–orbit interaction.

arXiv:2012.13914•Journal of Applied Physics•Oct 19, 2020•1 citation

Photo-assisted spin transport in double quantum dots with spin–orbit interaction

David Fernández-Fernández, Jordi Picó-Cortés, Sergio Vela Liñán +1 more

Abstract We investigate the effect of spin–orbit interaction on the intra- and interdot particle dynamics of a double quantum dot (QD) under ac electric fields. The former is modeled as an effective ac magnetic field that produces electric-dipole spin resonance transitions, while the latter is introduced via spin-flip tunneling amplitudes. We observe the appearance of non-trivial spin-polarized dark states (DSs), arising from an ac-induced interference between photo-assisted spin-conserving and spin-flip tunneling processes. These DSs can be employed to precisely measure the spin–orbit coupling in QD systems. Furthermore, we show that the interplay between photo-assisted transitions and spin-flip tunneling enables the system to operate as a highly tunable spin filter. Finally, we investigate the operation of the system as a resonant flopping-mode qubit for arbitrary ac voltage amplitudes, allowing for high tunability and enhanced qubit control possibilities.

arXiv:2302.12272•Journal of Physics Materials•May 2, 2023•7 citations

Two-photon absorption by a quantum dot pair

Michael Scheibner, Sophia E. Economou, Ilya V. Ponomarev +3 more

The biexciton absorption spectrum of a pair of InAs/GaAs quantum dots is being studied by photoluminescence excitation spectroscopy. An absorption resonance with the characteristics of an instantaneous two-photon process reveals a coherent interdot two-photon transition. Pauli-selective tunneling is being used to demonstrate the transduction of the two-photon coherence into a nonlocal spin singlet state. The two-photon transition can be tuned spectrally by electric field, enabling amplification of its transition strength.

Physical Review B•Aug 31, 2015•9 citations

Coherent spin rotations in open driven double quantum dots

Rafael Sánchez, Carlos López-Monís, Gloria Platero

We analyze coherent spin rotations in a dc biased double quantum dot driven by crossed dc and ac magnetic fields. In this configuration, spatial delocalization due to interdot tunneling competes with intradot spin rotations induced by the time dependent magnetic field, giving rise to a complicated time dependent behavior of the tunneling current. When the Zeeman splitting has the same value in both dots and spin flip is negligible, the electrons remain in the triplet subspace performing coherent spin rotations and current does not flow. This electronic trapping is removed either by finite spin relaxation or when the Zeeman splitting is different in each quantum dot. In the last case, we will show that by applying a resonant bichromatic magnetic field, the electrons become trapped in a coherent superposition of states and electronic transport is blocked. Then, manipulating ac magnetic fields allows one to drive electrons to perform coherent spin rotations which can be unambiguously detected by direct measurement of the tunneling current.

arXiv:0707.4636•Physical Review B•Apr 7, 2008•24 citations

Directly visualizing the energy level structure of quantum dot molecules

Heun Mo Yoo, Tanner M. Janda, Connor Nasseraddin +1 more

The orbital, spin and valley degrees of freedom in silicon quantum dots support many modes of spin qubit operation. However, it is generally challenging to obtain information about the energy level spectrum over large ranges of parameter space. We demonstrate a form of spectroscopy that is capable of mapping the energy level structure of a double quantum dot as a function of level detuning, interdot tunnel coupling, and magnetic field. In the one electron regime, we directly observe the transition from the atom like energy levels of isolated quantum dots to molecular like bonding and anti bonding states with increasing interdot tunnel coupling. We also resolve the Zeeman splitting of ground and excited valley states in a magnetic field. In the two electron regime, we gain access to the detuning dependent singlet triplet splitting. Our work may be extended to a broader class of systems, such as strong spin-orbit materials or proximitized quantum dots, allowing the direct extraction of various energy gaps.

cond-mat.mes-hallCross-listedarXiv:2604.00232•Apr 2, 2026

Microwave-Resonator-Detected Excited-State Spectroscopy of a Double Quantum Dot

Ming-Bo Chen, Shun-Li Jiang, Ning Wang +6 more

As an application in circuit quantum electrodynamics coupled systems, superconducting resonators play an important role in high-sensitivity measurements in a superconducting-semiconductor hybrid architecture. Taking advantage of a high-impedance $\mathrm{Nb}\text{\ensuremath{-}}\mathrm{Ti}\text{\ensuremath{-}}\mathrm{N}$ resonator, we perform excited-state spectroscopy on a $\mathrm{Ga}\mathrm{As}$ double quantum dot (DQD) by applying voltage pulses to one gate electrode. The pulse train modulates the DQD energy detuning and gives rise to charge state transitions at zero detuning. Benefiting from the outstanding sensitivity of the resonator, we distinguish different spin-state transitions in the energy spectrum according to the Pauli exclusion principle. Furthermore, we experimentally study how the interdot tunneling rate modifies the resonator response. The experimental results are consistent with the simulated spectra based on our model.

arXiv:2102.08169•Physical Review Applied•Apr 28, 2021•11 citations
Transport spectroscopy of two-spin states in a double quantum dot can be performed by an ac electric field which tunes the energy detuning. However, a problem arises when the transition rate between the states is small and, consequently, the ac-induced current is suppressed. Here we show that if the ac field tunes the interdot tunnel barrier, then for large detuning the transition rate increases drastically, resulting in high current. Multiphoton resonances are enhanced by orders of magnitude. Our study demonstrates an efficient way for fast two-spin transitions.
We study the AC field induced current peaks of a spin-blockaded double quantum dot with spin–orbit interaction. The AC field modulates either the interdot tunnel coupling or the energy detuning, and we choose the AC field frequency range to induce two singlet–triplet transitions giving rise to two current peaks. We show that for a large detuning, the two current peaks can be significantly stronger when the AC field modulates the tunnel coupling, thus making the detection of the spin–orbit gap more efficient. We also demonstrate the importance of the time dependence of the spin–orbit interaction.
Abstract We investigate the effect of spin–orbit interaction on the intra- and interdot particle dynamics of a double quantum dot (QD) under ac electric fields. The former is modeled as an effective ac magnetic field that produces electric-dipole spin resonance transitions, while the latter is introduced via spin-flip tunneling amplitudes. We observe the appearance of non-trivial spin-polarized dark states (DSs), arising from an ac-induced interference between photo-assisted spin-conserving and spin-flip tunneling processes. These DSs can be employed to precisely measure the spin–orbit coupling in QD systems. Furthermore, we show that the interplay between photo-assisted transitions and spin-flip tunneling enables the system to operate as a highly tunable spin filter. Finally, we investigate the operation of the system as a resonant flopping-mode qubit for arbitrary ac voltage amplitudes, allowing for high tunability and enhanced qubit control possibilities.
The biexciton absorption spectrum of a pair of InAs/GaAs quantum dots is being studied by photoluminescence excitation spectroscopy. An absorption resonance with the characteristics of an instantaneous two-photon process reveals a coherent interdot two-photon transition. Pauli-selective tunneling is being used to demonstrate the transduction of the two-photon coherence into a nonlocal spin singlet state. The two-photon transition can be tuned spectrally by electric field, enabling amplification of its transition strength.
We analyze coherent spin rotations in a dc biased double quantum dot driven by crossed dc and ac magnetic fields. In this configuration, spatial delocalization due to interdot tunneling competes with intradot spin rotations induced by the time dependent magnetic field, giving rise to a complicated time dependent behavior of the tunneling current. When the Zeeman splitting has the same value in both dots and spin flip is negligible, the electrons remain in the triplet subspace performing coherent spin rotations and current does not flow. This electronic trapping is removed either by finite spin relaxation or when the Zeeman splitting is different in each quantum dot. In the last case, we will show that by applying a resonant bichromatic magnetic field, the electrons become trapped in a coherent superposition of states and electronic transport is blocked. Then, manipulating ac magnetic fields allows one to drive electrons to perform coherent spin rotations which can be unambiguously detected by direct measurement of the tunneling current.
The orbital, spin and valley degrees of freedom in silicon quantum dots support many modes of spin qubit operation. However, it is generally challenging to obtain information about the energy level spectrum over large ranges of parameter space. We demonstrate a form of spectroscopy that is capable of mapping the energy level structure of a double quantum dot as a function of level detuning, interdot tunnel coupling, and magnetic field. In the one electron regime, we directly observe the transition from the atom like energy levels of isolated quantum dots to molecular like bonding and anti bonding states with increasing interdot tunnel coupling. We also resolve the Zeeman splitting of ground and excited valley states in a magnetic field. In the two electron regime, we gain access to the detuning dependent singlet triplet splitting. Our work may be extended to a broader class of systems, such as strong spin-orbit materials or proximitized quantum dots, allowing the direct extraction of various energy gaps.
As an application in circuit quantum electrodynamics coupled systems, superconducting resonators play an important role in high-sensitivity measurements in a superconducting-semiconductor hybrid architecture. Taking advantage of a high-impedance $\mathrm{Nb}\text{\ensuremath{-}}\mathrm{Ti}\text{\ensuremath{-}}\mathrm{N}$ resonator, we perform excited-state spectroscopy on a GaAs\mathrm{Ga}\mathrm{As}GaAs double quantum dot (DQD) by applying voltage pulses to one gate electrode. The pulse train modulates the DQD energy detuning and gives rise to charge state transitions at zero detuning. Benefiting from the outstanding sensitivity of the resonator, we distinguish different spin-state transitions in the energy spectrum according to the Pauli exclusion principle. Furthermore, we experimentally study how the interdot tunneling rate modifies the resonator response. The experimental results are consistent with the simulated spectra based on our model.