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

Two-Dimensional Time-Domain Spectroscopy for Determination of Energy and Momentum Relaxation Rates of Hydrogen-Like Donor States in Germanium

Th. B. Gill, Pavlov, Sergey, C. S. Kidd, Paul Dean, A. D. Burnett, A. Dunn, L. Li, N. V. Abrosimov, Heinz‐Wilhelm Hübers, EH Linfield, A. G. Davies, Joshua R. Freeman

Published Jan 1, 2024• 0 citations
OpenAlex

Abstract

We present measurements of coherence times of excited states of hydrogen-like arsenic impurities in germanium (Ge:As) using a table-top 2D-TDS system. We observe coherent population transfer and decay of transitions from the 2p0 and 2p± states by fitting the detected coherent nonlinear response with the known intracenter transition frequencies. Coherences between excited electronic states that are not visible via conventional single frequency pump-probe measurements are also observed in the off-diagonal resonances in the 2D frequency-domain map.

Related papers

2D Time-Domain Spectroscopy for Determination of Energy and Momentum Relaxation Rates of Hydrogen-Like Donor States in Germanium

T. B. Gill, Sergei G. Pavlov, C. Kidd +9 more

High Resolution Image Download MS PowerPoint Slide We present measurements of the coherence times of excited states of hydrogen-like arsenic impurities in germanium (Ge:As) using a table-top two-dimensional time-domain spectroscopy (2D-TDS) system. We show that this laboratory system is capable of resolving the coherence lifetimes of atomic-like excited levels of impurity centers in semiconductors, such as those used in solid-state quantum information technologies, on a subpicosecond time scale. By fitting the coherent nonlinear response of the system with the known intracenter transition frequencies, we are able to monitor coherent population transfer and decay of the transitions from the 2p 0 and 2p ± states for different low excitation pulse fields. Furthermore, by examining the off-diagonal resonances in the 2D frequency-domain map, we are able to identify coherences between excited electronic states that are not visible via conventional single-frequency pump–probe or Hahn-echo measurements.

ACS Photonics•Mar 27, 2024•1 citation

On the Intracenter Relaxation of Shallow Arsenic Donors in Stressed Germanium. Population Inversion under Optical Excitation

Veniamin V. Tsyplenkov, V. N. Shastin

Abstract The relaxation rates of lower excited states 1s(T), 2p0, 2s, 3p0, and 2p± of arsenic donors in a germanium crystal are calculated upon the interaction with long-wavelength acoustic phonons depending on the uniaxial stress in the crystallographic direction [111]. The populations of states under optical excitation are estimated for calculated times. It is shown theoretically that optical excitation of the medium forms an inverse population of arsenic donor levels and leads to the possibility of the implementation of a four-level laser scheme with the radiative transition between 2p states and the 1s triplet state at zero strain. The estimated value of the expected gain in the medium under optical excitation conditions by CO2 laser radiation in the medium at a donor concentration of 2 × 1015 cm–3 is ~0.35 cm–1 at a frequency of 1.98 THz if the laser transition is 2p± → 1s(T) and 1.25 THz if the laser transition is 2p0 → 1s(T).

Semiconductors•Nov 7, 2018•12 citations

Ramsey Fringes in Germanium Doped with Arsenic Donors

Roman Kh. Zhukavin, P. A. Bushuikin, V. D. Kukotenko +10 more

Abstract The results of observation of Ramsey oscillations in germanium doped with arsenic donors detected by photothermal ionization of Coulomb centers are presented. To excite quantum coherent superpositions of the states at the transition 1s(A1)–2p0 the Novosibirsk free electron laser radiation was used. The results are analyzed using a theoretical model using several key parameters of the experiment.

Bulletin of the Russian Academy of Sciences Physics•Jun 1, 2023•0 citations

Quantum control in silicon using coherent THz pulses

Stephen A. Lynch, P. Thornton Greenland, Alexander F. G. van der Meer +5 more

It has long been known that shallow donors such as phosphorous and the other group-V elements, have a hydrogen-like optical spectrum. The main difference is that while the spectrum of atomic hydrogen lies in the visible band, the spectrum of shallow donors in silicon is downshifted to the THz frequency band. This is a direct consequence of the reduced Coulomb attraction seen by the loosely bound electron because the core electrons shield the positive donor atom nucleus, and because the electron is now moving in a dielectric material. While spectroscopy has already revealed much about the energy level structure, very little was known about the temporal dynamics of the system until now. We have used THz pulses from the FELIX free electron laser to probe these hydrogen-like levels. By exploiting the well-known pump-probe technique we have measured the characteristic lifetimes of the excited Rydberg states and found them to be of the order 200 ps. Then, by making subtle changes to the geometry of the pump-probe experimental setup we demonstrate the existence of a THz photon echo. The photon echo is a purely quantum phenomenon with no classical analogue, and it allows us to study the quantum state of the donor electron. We then show, using the photon echo, that it is possible to create a coherent superposition of the ground and excited state of the donor. Measuring the photon echo is important because it can also be used to measure a second important characteristic lifetime of the silicon-donor system, the phase decoherence time.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Oct 15, 2012•0 citations

Внутрицентровая релаксация мелких доноров мышьяка в деформированном германии. Инверсия населенностей при оптическом возбуждении

В.В. Цыпленков, В.Н. Шастин

AbstractThe relaxation rates of lower excited states 1 s ( T ), 2 p _0, 2 s , 3 p _0, and 2 p _± of arsenic donors in a germanium crystal are calculated upon the interaction with long-wavelength acoustic phonons depending on the uniaxial stress in the crystallographic direction [111]. The populations of states under optical excitation are estimated for calculated times. It is shown theoretically that optical excitation of the medium forms an inverse population of arsenic donor levels and leads to the possibility of the implementation of a four-level laser scheme with the radiative transition between 2 p states and the 1 s triplet state at zero strain. The estimated value of the expected gain in the medium under optical excitation conditions by CO_2 laser radiation in the medium at a donor concentration of 2 × 10^15 cm^–3 is ~0.35 cm^–1 at a frequency of 1.98 THz if the laser transition is 2 p _± → 1 s ( T ) and 1.25 THz if the laser transition is 2 p _0 → 1 s ( T ).

Физика и техника полупроводников•Jan 1, 2018•0 citations

Weak probe readout of coherent impurity orbital superpositions in silicon

K. L. Litvinenko, P. Thornton Greenland, Britta Redlich +3 more

Pump-probe spectroscopy is the most common time-resolved technique for investigation of electronic dynamics, and the results provide the incoherent population decay time ${T}_{1}$. Here we use a modified pump-probe experiment to investigate coherent dynamics, and we demonstrate this with a measurement of the inhomogeneous dephasing time ${T}_{2}^{*}$ for phosphorus impurities in silicon. The pulse sequence produces the same information as previous coherent all-optical (photon-echo-based) techniques but is simpler. The probe signal strength is first order in the pulse area but its effect on the target state is only second order, meaning that it does not demolish the quantum information. We propose simple extensions to the technique to measure the homogeneous dephasing time ${T}_{2}$, or to perform tomography of the target qubit.

Physical review. B./Physical review. B•Dec 20, 2016•2 citations
We present measurements of coherence times of excited states of hydrogen-like arsenic impurities in germanium (Ge:As) using a table-top 2D-TDS system. We observe coherent population transfer and decay of transitions from the 2p0 and 2p± states by fitting the detected coherent nonlinear response with the known intracenter transition frequencies. Coherences between excited electronic states that are not visible via conventional single frequency pump-probe measurements are also observed in the off-diagonal resonances in the 2D frequency-domain map.
High Resolution Image Download MS PowerPoint Slide We present measurements of the coherence times of excited states of hydrogen-like arsenic impurities in germanium (Ge:As) using a table-top two-dimensional time-domain spectroscopy (2D-TDS) system. We show that this laboratory system is capable of resolving the coherence lifetimes of atomic-like excited levels of impurity centers in semiconductors, such as those used in solid-state quantum information technologies, on a subpicosecond time scale. By fitting the coherent nonlinear response of the system with the known intracenter transition frequencies, we are able to monitor coherent population transfer and decay of the transitions from the 2p 0 and 2p ± states for different low excitation pulse fields. Furthermore, by examining the off-diagonal resonances in the 2D frequency-domain map, we are able to identify coherences between excited electronic states that are not visible via conventional single-frequency pump–probe or Hahn-echo measurements.
Abstract The relaxation rates of lower excited states 1s(T), 2p0, 2s, 3p0, and 2p± of arsenic donors in a germanium crystal are calculated upon the interaction with long-wavelength acoustic phonons depending on the uniaxial stress in the crystallographic direction [111]. The populations of states under optical excitation are estimated for calculated times. It is shown theoretically that optical excitation of the medium forms an inverse population of arsenic donor levels and leads to the possibility of the implementation of a four-level laser scheme with the radiative transition between 2p states and the 1s triplet state at zero strain. The estimated value of the expected gain in the medium under optical excitation conditions by CO2 laser radiation in the medium at a donor concentration of 2 × 1015 cm–3 is ~0.35 cm–1 at a frequency of 1.98 THz if the laser transition is 2p± → 1s(T) and 1.25 THz if the laser transition is 2p0 → 1s(T).
It has long been known that shallow donors such as phosphorous and the other group-V elements, have a hydrogen-like optical spectrum. The main difference is that while the spectrum of atomic hydrogen lies in the visible band, the spectrum of shallow donors in silicon is downshifted to the THz frequency band. This is a direct consequence of the reduced Coulomb attraction seen by the loosely bound electron because the core electrons shield the positive donor atom nucleus, and because the electron is now moving in a dielectric material. While spectroscopy has already revealed much about the energy level structure, very little was known about the temporal dynamics of the system until now. We have used THz pulses from the FELIX free electron laser to probe these hydrogen-like levels. By exploiting the well-known pump-probe technique we have measured the characteristic lifetimes of the excited Rydberg states and found them to be of the order 200 ps. Then, by making subtle changes to the geometry of the pump-probe experimental setup we demonstrate the existence of a THz photon echo. The photon echo is a purely quantum phenomenon with no classical analogue, and it allows us to study the quantum state of the donor electron. We then show, using the photon echo, that it is possible to create a coherent superposition of the ground and excited state of the donor. Measuring the photon echo is important because it can also be used to measure a second important characteristic lifetime of the silicon-donor system, the phase decoherence time.
AbstractThe relaxation rates of lower excited states 1 s ( T ), 2 p _0, 2 s , 3 p _0, and 2 p _± of arsenic donors in a germanium crystal are calculated upon the interaction with long-wavelength acoustic phonons depending on the uniaxial stress in the crystallographic direction [111]. The populations of states under optical excitation are estimated for calculated times. It is shown theoretically that optical excitation of the medium forms an inverse population of arsenic donor levels and leads to the possibility of the implementation of a four-level laser scheme with the radiative transition between 2 p states and the 1 s triplet state at zero strain. The estimated value of the expected gain in the medium under optical excitation conditions by CO_2 laser radiation in the medium at a donor concentration of 2 × 10^15 cm^–3 is ~0.35 cm^–1 at a frequency of 1.98 THz if the laser transition is 2 p _± → 1 s ( T ) and 1.25 THz if the laser transition is 2 p _0 → 1 s ( T ).
Pump-probe spectroscopy is the most common time-resolved technique for investigation of electronic dynamics, and the results provide the incoherent population decay time T1{T}_{1}T1​. Here we use a modified pump-probe experiment to investigate coherent dynamics, and we demonstrate this with a measurement of the inhomogeneous dephasing time T2∗{T}_{2}^{*}T2∗​ for phosphorus impurities in silicon. The pulse sequence produces the same information as previous coherent all-optical (photon-echo-based) techniques but is simpler. The probe signal strength is first order in the pulse area but its effect on the target state is only second order, meaning that it does not demolish the quantum information. We propose simple extensions to the technique to measure the homogeneous dephasing time T2{T}_{2}T2​, or to perform tomography of the target qubit.