Sergei Studenikin | University of Waterloo (original) (raw)
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Papers by Sergei Studenikin
Physical Review B
Difference in g factors in multidot structures can form the basis of dot-selective spin manipulat... more Difference in g factors in multidot structures can form the basis of dot-selective spin manipulation under global microwave irradiation. Employing electric dipole spin resonance facilitated by strong spin-orbit interaction (SOI), we observe differences in the extracted values of the single-hole effective g factors of the constituent quantum dots of a GaAs/AlGaAs double quantum dot device at the level of ∼5%-10%.
Single-electron charging in an individual InAs quantum dot was observed by electrostatic force me... more Single-electron charging in an individual InAs quantum dot was observed by electrostatic force measurements with an atomic-force microscope (AFM). The resonant frequency shift and the dissipated energy of an oscillating AFM cantilever were measured as a function of the tip-back electrode voltage, and the resulting spectra show distinct jumps when the tip was positioned above the dot. The observed jumps in the frequency shift, with corresponding peaks in dissipation, are attributed to a single-electron tunneling between the dot and the back electrode governed by the Coulomb blockade effect, and are consistent with a model based on the free energy of the system. The observed phenomenon may be regarded as the "force version" of the Coulomb blockade effect.
We have demonstrated Landau-Zener-Stuckelberg oscillations in a triple quantum dot circuit relate... more We have demonstrated Landau-Zener-Stuckelberg oscillations in a triple quantum dot circuit related to pairs of triple quantum dot states. Different initialization schemes and pulse shapes involving all three dots will be discussed. However, the complexity of a triple quantum dot ...
Semiconductor Science and Technology
Applied Physics Letters
Quantum confinement and manipulation of charge carriers are critical for achieving devices practi... more Quantum confinement and manipulation of charge carriers are critical for achieving devices practical for quantum technologies. The interplay between electron spin and valley, as well as the possibility to address their quantum states electrically and optically, makes twodimensional (2D) transition metal dichalcogenides an emerging platform for the development of quantum devices. In this work, we fabricate devices based on heterostructures of layered 2D materials, in which we realize gate-controlled tungsten diselenide (WSe 2) hole quantum dots. We discuss the observed mesoscopic transport features related to the emergence of quantum dots in the WSe 2 device channel, and we compare them to a theoretical model.
Communications Physics
Electrical tunability of the g$$g-factor of a confined spin is a long-time goal of the spin qub... more Electrical tunability of the g$$g-factor of a confined spin is a long-time goal of the spin qubit field. Here we utilize the electric dipole spin resonance (EDSR) to demonstrate it in a gated GaAs double-dot device confining a hole. This tunability is a consequence of the strong spin-orbit interaction (SOI) in the GaAs valence band. The SOI enables a spin-flip interdot tunneling, which, in combination with the simple spin-conserving charge transport leads to the formation of tunable hybrid spin-orbit molecular states. EDSR is used to demonstrate that the gap separating the two lowest energy states changes its character from a charge-like to a spin-like excitation as a function of interdot detuning or magnetic field. In the spin-like regime, the gap can be characterized by the effective g$$g-factor, which differs from the bulk value owing to spin-charge hybridization, and can be tuned smoothly and sensitively by gate voltages.
Physical review letters, Jan 18, 2018
We perform Landau-Zener-Stückelberg-Majorana (LZSM) spectroscopy on a system with strong spin-orb... more We perform Landau-Zener-Stückelberg-Majorana (LZSM) spectroscopy on a system with strong spin-orbit interaction (SOI), realized as a single hole confined in a gated double quantum dot. Analogous to electron systems, at a magnetic field B=0 and high modulation frequencies, we observe photon-assisted tunneling between dots, which smoothly evolves into the typical LZSM funnel-shaped interference pattern as the frequency is decreased. In contrast to electrons, the SOI enables an additional, efficient spin-flip interdot tunneling channel, introducing a distinct interference pattern at finite B. Magnetotransport spectra at low-frequency LZSM driving show the two channels to be equally coherent. High-frequency LZSM driving reveals complex photon-assisted tunneling pathways, both spin conserving and spin flip, which form closed loops at critical magnetic fields. In one such loop, an arbitrary hole spin state is inverted, opening the way toward its all-electrical manipulation.
International Journal of Modern Physics B
We have performed microwave absorption and near-field reflection experiments on a high mobility G... more We have performed microwave absorption and near-field reflection experiments on a high mobility GaAs / AlGaAs heterostructure for the same conditions for which Microwave-Induced Resistance Oscillations (MIROs) are observed. It is shown that the electrodynamic aspect of the problem is important in these experiments. In the absorption experiments a broad CR line was observed due to a large reflection from the highly conductive electron gas. There were no additional features observed related to absorption at harmonics of the cyclotron resonance. In near-field reflection experiments a very different oscillation pattern was revealed when compared to MIROs. The oscillation pattern observed in the reflection experiments is probably due to plasma effects occurring in a finite-size sample. The whole microscopic picture of MIROs is more complicated than simply a resonant absorption at harmonics of the cyclotron resonance. Nevertheless, the experimental observations are in good agreement with ...
physica status solidi (c)
ABSTRACT In this paper we describe our recent experiments on coherent manipulation of electron sp... more ABSTRACT In this paper we describe our recent experiments on coherent manipulation of electron spin states formed in a highly tunable GaAs/AlGaAs triple quantum dot device. The coherent evolution of spin states is achieved by using fast pulses from an initialization point in the (201) charge configuration region of the stability diagram. We demonstrate the versatility of the triple dot system capable of tuning to different regimes controlled by the width of the (111) region and pulse parameters. In particular we observe ' 1/2 -Q 3/2 (analogue of S-T + in a double dot) and ' 1/2 -1/2 exchange driven oscillations from both sides of the stability diagram involving all three spins.
AIP Conference Proceedings
ABSTRACT The coupling between the Zeeman splitting and the Rashba spin-orbit interaction, with ti... more ABSTRACT The coupling between the Zeeman splitting and the Rashba spin-orbit interaction, with tilted magnetic fields, has been investigated in a gated (InGa)As/InP quantum well structure. It is demonstrated that the “spin zeroes” in the Shubnikov-de Haas oscillations can be enhanced by tilt and why they are not always present. A simple expression is given that allows the Rashba parameter to be extracted from the position of the spin zeroes in tilted fields. Values of the parameter obtained in this way are in good agreement with those estimated from the width of the weak anti-localisation peak.
Physical Review B
We investigate how the voltage pulse period affects the visibility of coherent S-T+ Landau-Zener-... more We investigate how the voltage pulse period affects the visibility of coherent S-T+ Landau-Zener-Stückelberg oscillations in a double quantum dot formed within a triple quantum dot circuit. We find both experimentally and theoretically that there exist conditions for achieving maximum visibility which depend on the hyperfine splitting and on the ratio of the pulse period to the relaxation time.
• Recent non-linear r xx =dV xx /dI (MIRO, ZRS, ZDRS, HIROs, PIROs…) and spectral diffusion exper... more • Recent non-linear r xx =dV xx /dI (MIRO, ZRS, ZDRS, HIROs, PIROs…) and spectral diffusion experiments on high mobility GaAs/AlGaAs samples 1-5 • High quality InGaAs/InP QW structures become available: large g*-factor and large spin-orbit coupling are promising for spin-manipulation experiments • Revisit QHE breakdown experiments, but in non-linear transport 6,7
J Luminesc, 2001
Thin films of yttrium oxide doped separately with Eu 3+ , Tb 3+ and Tm 3+ were deposited by spray... more Thin films of yttrium oxide doped separately with Eu 3+ , Tb 3+ and Tm 3+ were deposited by spray pyrolysis. The effect of preparation conditions on the structural and cathodoluminescent (CL) properties of the thin films was investigated. Films containing Eu 3+ , Tb 3+ and Tm 3+ emitted red, green and blue colors, respectively. Films of yttrium oxide doped with Tm were evaluated in detail. The blue emission of these films had CIE chromaticity coordinates of x ¼ 0:158 and y ¼ 0:150 with a dominant wavelength of 476 nm and a color purity of 78% compared to CIE Standard Source C. The CL intensity of the films under 5 kV beam excitation and a current density of 5 mA/cm 2 depended strongly on annealing conditions and thulium doping concentration. For Tm-doped films the maximum luminance was 30.4 cd/m 2 and there was a linear relationship between the CL intensity and excitation voltage. A luminance of 255 cd/m 2 was obtained for the Eu-doped film. The dominant wavelength was 604 nm with 100% purity, and x ¼ 0:645 and y ¼ 0:357. The luminance for the Tb-doped film was 72 cd/m 2 with a dominant wavelength of 547 nm and 77% purity.
We report charge detection studies of a lateral double quantum dot with controllable charge state... more We report charge detection studies of a lateral double quantum dot with controllable charge states and tunable tunnel coupling. Using an integrated electrometer, we characterize the equilibrium state of a single electron trapped in the doubled-dot (artificial H2+ molecule) by measuring the average occupation of one dot. We present a model where the electrostatic coupling between the molecule and the sensor is taken into account explicitly. From the measurements, we extract the temperature of the isolated electron and the tunnel coupling energy. It is found that this coupling can be tuned between 0 and 60 micro electron-volt in our device.
Physical Review B
Difference in g factors in multidot structures can form the basis of dot-selective spin manipulat... more Difference in g factors in multidot structures can form the basis of dot-selective spin manipulation under global microwave irradiation. Employing electric dipole spin resonance facilitated by strong spin-orbit interaction (SOI), we observe differences in the extracted values of the single-hole effective g factors of the constituent quantum dots of a GaAs/AlGaAs double quantum dot device at the level of ∼5%-10%.
Single-electron charging in an individual InAs quantum dot was observed by electrostatic force me... more Single-electron charging in an individual InAs quantum dot was observed by electrostatic force measurements with an atomic-force microscope (AFM). The resonant frequency shift and the dissipated energy of an oscillating AFM cantilever were measured as a function of the tip-back electrode voltage, and the resulting spectra show distinct jumps when the tip was positioned above the dot. The observed jumps in the frequency shift, with corresponding peaks in dissipation, are attributed to a single-electron tunneling between the dot and the back electrode governed by the Coulomb blockade effect, and are consistent with a model based on the free energy of the system. The observed phenomenon may be regarded as the "force version" of the Coulomb blockade effect.
We have demonstrated Landau-Zener-Stuckelberg oscillations in a triple quantum dot circuit relate... more We have demonstrated Landau-Zener-Stuckelberg oscillations in a triple quantum dot circuit related to pairs of triple quantum dot states. Different initialization schemes and pulse shapes involving all three dots will be discussed. However, the complexity of a triple quantum dot ...
Semiconductor Science and Technology
Applied Physics Letters
Quantum confinement and manipulation of charge carriers are critical for achieving devices practi... more Quantum confinement and manipulation of charge carriers are critical for achieving devices practical for quantum technologies. The interplay between electron spin and valley, as well as the possibility to address their quantum states electrically and optically, makes twodimensional (2D) transition metal dichalcogenides an emerging platform for the development of quantum devices. In this work, we fabricate devices based on heterostructures of layered 2D materials, in which we realize gate-controlled tungsten diselenide (WSe 2) hole quantum dots. We discuss the observed mesoscopic transport features related to the emergence of quantum dots in the WSe 2 device channel, and we compare them to a theoretical model.
Communications Physics
Electrical tunability of the g$$g-factor of a confined spin is a long-time goal of the spin qub... more Electrical tunability of the g$$g-factor of a confined spin is a long-time goal of the spin qubit field. Here we utilize the electric dipole spin resonance (EDSR) to demonstrate it in a gated GaAs double-dot device confining a hole. This tunability is a consequence of the strong spin-orbit interaction (SOI) in the GaAs valence band. The SOI enables a spin-flip interdot tunneling, which, in combination with the simple spin-conserving charge transport leads to the formation of tunable hybrid spin-orbit molecular states. EDSR is used to demonstrate that the gap separating the two lowest energy states changes its character from a charge-like to a spin-like excitation as a function of interdot detuning or magnetic field. In the spin-like regime, the gap can be characterized by the effective g$$g-factor, which differs from the bulk value owing to spin-charge hybridization, and can be tuned smoothly and sensitively by gate voltages.
Physical review letters, Jan 18, 2018
We perform Landau-Zener-Stückelberg-Majorana (LZSM) spectroscopy on a system with strong spin-orb... more We perform Landau-Zener-Stückelberg-Majorana (LZSM) spectroscopy on a system with strong spin-orbit interaction (SOI), realized as a single hole confined in a gated double quantum dot. Analogous to electron systems, at a magnetic field B=0 and high modulation frequencies, we observe photon-assisted tunneling between dots, which smoothly evolves into the typical LZSM funnel-shaped interference pattern as the frequency is decreased. In contrast to electrons, the SOI enables an additional, efficient spin-flip interdot tunneling channel, introducing a distinct interference pattern at finite B. Magnetotransport spectra at low-frequency LZSM driving show the two channels to be equally coherent. High-frequency LZSM driving reveals complex photon-assisted tunneling pathways, both spin conserving and spin flip, which form closed loops at critical magnetic fields. In one such loop, an arbitrary hole spin state is inverted, opening the way toward its all-electrical manipulation.
International Journal of Modern Physics B
We have performed microwave absorption and near-field reflection experiments on a high mobility G... more We have performed microwave absorption and near-field reflection experiments on a high mobility GaAs / AlGaAs heterostructure for the same conditions for which Microwave-Induced Resistance Oscillations (MIROs) are observed. It is shown that the electrodynamic aspect of the problem is important in these experiments. In the absorption experiments a broad CR line was observed due to a large reflection from the highly conductive electron gas. There were no additional features observed related to absorption at harmonics of the cyclotron resonance. In near-field reflection experiments a very different oscillation pattern was revealed when compared to MIROs. The oscillation pattern observed in the reflection experiments is probably due to plasma effects occurring in a finite-size sample. The whole microscopic picture of MIROs is more complicated than simply a resonant absorption at harmonics of the cyclotron resonance. Nevertheless, the experimental observations are in good agreement with ...
physica status solidi (c)
ABSTRACT In this paper we describe our recent experiments on coherent manipulation of electron sp... more ABSTRACT In this paper we describe our recent experiments on coherent manipulation of electron spin states formed in a highly tunable GaAs/AlGaAs triple quantum dot device. The coherent evolution of spin states is achieved by using fast pulses from an initialization point in the (201) charge configuration region of the stability diagram. We demonstrate the versatility of the triple dot system capable of tuning to different regimes controlled by the width of the (111) region and pulse parameters. In particular we observe ' 1/2 -Q 3/2 (analogue of S-T + in a double dot) and ' 1/2 -1/2 exchange driven oscillations from both sides of the stability diagram involving all three spins.
AIP Conference Proceedings
ABSTRACT The coupling between the Zeeman splitting and the Rashba spin-orbit interaction, with ti... more ABSTRACT The coupling between the Zeeman splitting and the Rashba spin-orbit interaction, with tilted magnetic fields, has been investigated in a gated (InGa)As/InP quantum well structure. It is demonstrated that the “spin zeroes” in the Shubnikov-de Haas oscillations can be enhanced by tilt and why they are not always present. A simple expression is given that allows the Rashba parameter to be extracted from the position of the spin zeroes in tilted fields. Values of the parameter obtained in this way are in good agreement with those estimated from the width of the weak anti-localisation peak.
Physical Review B
We investigate how the voltage pulse period affects the visibility of coherent S-T+ Landau-Zener-... more We investigate how the voltage pulse period affects the visibility of coherent S-T+ Landau-Zener-Stückelberg oscillations in a double quantum dot formed within a triple quantum dot circuit. We find both experimentally and theoretically that there exist conditions for achieving maximum visibility which depend on the hyperfine splitting and on the ratio of the pulse period to the relaxation time.
• Recent non-linear r xx =dV xx /dI (MIRO, ZRS, ZDRS, HIROs, PIROs…) and spectral diffusion exper... more • Recent non-linear r xx =dV xx /dI (MIRO, ZRS, ZDRS, HIROs, PIROs…) and spectral diffusion experiments on high mobility GaAs/AlGaAs samples 1-5 • High quality InGaAs/InP QW structures become available: large g*-factor and large spin-orbit coupling are promising for spin-manipulation experiments • Revisit QHE breakdown experiments, but in non-linear transport 6,7
J Luminesc, 2001
Thin films of yttrium oxide doped separately with Eu 3+ , Tb 3+ and Tm 3+ were deposited by spray... more Thin films of yttrium oxide doped separately with Eu 3+ , Tb 3+ and Tm 3+ were deposited by spray pyrolysis. The effect of preparation conditions on the structural and cathodoluminescent (CL) properties of the thin films was investigated. Films containing Eu 3+ , Tb 3+ and Tm 3+ emitted red, green and blue colors, respectively. Films of yttrium oxide doped with Tm were evaluated in detail. The blue emission of these films had CIE chromaticity coordinates of x ¼ 0:158 and y ¼ 0:150 with a dominant wavelength of 476 nm and a color purity of 78% compared to CIE Standard Source C. The CL intensity of the films under 5 kV beam excitation and a current density of 5 mA/cm 2 depended strongly on annealing conditions and thulium doping concentration. For Tm-doped films the maximum luminance was 30.4 cd/m 2 and there was a linear relationship between the CL intensity and excitation voltage. A luminance of 255 cd/m 2 was obtained for the Eu-doped film. The dominant wavelength was 604 nm with 100% purity, and x ¼ 0:645 and y ¼ 0:357. The luminance for the Tb-doped film was 72 cd/m 2 with a dominant wavelength of 547 nm and 77% purity.
We report charge detection studies of a lateral double quantum dot with controllable charge state... more We report charge detection studies of a lateral double quantum dot with controllable charge states and tunable tunnel coupling. Using an integrated electrometer, we characterize the equilibrium state of a single electron trapped in the doubled-dot (artificial H2+ molecule) by measuring the average occupation of one dot. We present a model where the electrostatic coupling between the molecule and the sensor is taken into account explicitly. From the measurements, we extract the temperature of the isolated electron and the tunnel coupling energy. It is found that this coupling can be tuned between 0 and 60 micro electron-volt in our device.