Article
Nanoscience & Nanotechnology
Pierre-Andre Mortemousque, Emmanuel Chanrion, Baptiste Jadot, Hanno Flentje, Arne Ludwig, Andreas D. Wieck, Matias Urdampilleta, Christopher Bauerle, Tristan Meunier
Summary: Controlling individual quantum objects organized in arrays is essential for scalable quantum information platforms. By integrating nearest-neighbour coupled semiconductor quantum dots in a 3 x 3 array with finely tuned virtual gate control, 2D coherent spin control has been achieved. Recent efforts in controlling electron spins in quantum dot arrays have led to the realization of quantum simulators and multielectron spin-coherent manipulations. However, demonstrating 2D scaling with a high connectivity of such implementations remains a challenge.
NATURE NANOTECHNOLOGY
(2021)
Article
Quantum Science & Technology
Martin Nurizzo, Baptiste Jadot, Pierre-Andre Mortemousque, Vivien Thiney, Emmanuel Chanrion, David Niegemann, Matthieu Dartiailh, Arne Ludwig, Andreas D. Wieck, Christopher Baeuerle, Matias Urdampilleta, Tristan Meunier
Summary: We propose a protocol to achieve complete spin state readout of a two-electron system in a double quantum dot probed by an electrometer. This is done through repetitive single-shot measurements using Pauli spin blockade and our ability to tune the detuning and interdot tunnel coupling on fast timescales. By performing three distinct manipulations and measurements, we can determine if the spins are in the S, T0, T+, or T- state. This work addresses an important challenge of reducing the overhead for spin readout in scaling up spin-qubit platforms.
Article
Multidisciplinary Sciences
Runyu Lu, Kaipeng Liu, Yue Ban
Summary: This paper focuses on the robust control of a singlet-triplet qubit in a nanowire double quantum dot using inverse engineering and shortcuts to adiabaticity (STA). The optimization of STA with respect to systematic errors and the application of optimal control techniques are explored.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Physics, Condensed Matter
Mustafa Kemal Bahar, Pinar Baser
Summary: This study investigates the nonlinear optical properties of InGaAs/GaAs Mathieu quantum dots (MQDs), focusing on nonlinear optical rectification (NOR), second harmonic generation (SHG), and third harmonic generation (THG). The effects of external fields and structural parameters on the MQD properties are examined, aiming to explain the NOR, SHG, and THG characteristics in response to changes in external fields and structural factors. The study also proposes a method to investigate the effects of the laser field and discusses the impacts of external fields and structural parameters on the coefficients of NOR, SHG, and THG. The optimality of the MQD structure for device design and applications is revealed through alternative parameter analysis.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Jianfu Han, Kai Huang, Xuanguang Su, Xiaofei Xiao, Xuemin Gong, Haibin Wang, Juexian Cao
Summary: PbS colloidal quantum dots (CQDs) usually suffer from low carrier mobility due to surface ligand isolation and defects. By combining PbS CQD photodiode with a carbon nanotube (CNT) film field-effect transistor (FET), a transistorized NIR photodetector with high performance and ultrahigh external quantum efficiency (EQE) is achieved.
Article
Physics, Condensed Matter
A. M. Maniero, F. V. Prudente, C. R. de Carvalho, Ginette Jalbert
Summary: In this study, we investigate the effect of different confinement potential profiles on a system of two coupled quantum dots containing two electrons under a uniform magnetic field. Specifically, we analyze the behavior of key physical quantities in a two-qubit quantum gate operation for two different confinement profiles mentioned in literature. Our aim is to determine the sensitivity of these physical quantities to the confinement profile and identify the critical magnetic field range for this issue.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Subhomoy Haldar, Harald Havir, Waqar Khan, Sebastian Lehmann, Claes Thelander, Kimberly A. Dick, Ville F. Maisi
Summary: We investigate the interaction between microwaves and a double quantum dot photodiode and observe wave-particle duality in photon-assisted tunneling. The experiments demonstrate that in the weak-drive limit, the absorption energy is determined by the energy of a single photon, whereas in the strong-drive limit, the energy scale is determined by the amplitude of the wave, leading to microwave-induced bias triangles. The transition between these two regimes is determined by the fine-structure constant of the system. The energetics are characterized here using the detuning conditions of the double dot system and stopping-potential measurements, which mimic the microwave version of the photoelectric effect.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Condensed Matter
M. Goudarzi, J. Karamdel, H. Hassanabadi, Sh Zorriasatein
Summary: We studied the non-relativistic particles of a two-dimensional two-electron quantum dot, considering the effects of harmonic plus linear terms and a spin interaction term. The solution of the system was obtained using the Quasi-Exactly-Solvable (QES) method, and we calculated the energy eigenstates and wave functions of the system in the presence of an external magnetic field.
SOLID STATE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
S. V. Aksenov
Summary: In this study, we investigate the interference transport features of a curved heterostructure in hybrid superconducting/semiconducting nanowires, considering the spatial inhomogeneity of the experimentally investigated samples. By analyzing a set of limiting cases, we highlight the interference properties unique to different types of Andreev bound states (ABSs), including bulk ABS, inhomogeneous ABS, and Majorana bound states (MBS). The features of the Aharonov-Bohm effect are particularly emphasized.
Article
Materials Science, Multidisciplinary
Grzegorz Michalek, Bogdan R. Bulka
Summary: The study analyzes the transient electron dynamics and Fano resonance formation over time in transport through a two quantum dot system in a T-shape geometry. It is found that the time evolution of the transport characteristics differs depending on the strength of inter-dot coupling.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Physics, Multidisciplinary
Suha Hadi, Amin Habbeb Al-Khursan
Summary: This study introduces a double quantum dot structure as an intermediate-band layer to improve solar cell performance for the first time. The research emphasizes the flexibility and importance of the double quantum dot layer, demonstrating that reducing quantum dot-quantum dot recombinations and increasing other recombinations can increase quantum efficiency.
Article
Nanoscience & Nanotechnology
S. Chaudhuri
Summary: The study analyzed the energy levels of two interacting electrons in a 2D quantum dot confined by a finite Gaussian potential and subjected to a uniform magnetic field, obtaining analytic results for the energy spectrum. The ground state transitions and energy as a function of magnetic field were calculated, compared with experimental data, and previous theoretical results.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Physics, Multidisciplinary
M. S. Linares, H. Vinck-Posada, Edgar A. Gomez
Summary: This paper explores the impact of an external magnetic field on the steady-state observables of a multi-excitonic quantum dot embedded in a bimodal optical cavity. By analyzing the occupations and dispersion relations of the dressed states, anti-crosses are discovered, indicating coupling between light and matter in the quantum system. By adjusting the tilt angle and intensity of the applied magnetic field, steady-state occupations can be manipulated for magnetic control in the solid-state quantum system.
Article
Optics
Nan Zhang, Xiangwei Qu, Quan Lyu, Kai Wang, Xiao Wei Sun
Summary: This study reports the fabrication of high-performance transparent quantum-dot light-emitting diodes using ZnO/ZnMgO inorganic double electron-transport layers. The ETLs effectively suppress excess electron injection and facilitate charge balance, leading to significant improvements in Tr-QLEDs development.
PHOTONICS RESEARCH
(2021)
Article
Electrochemistry
Marjanul Manjum, Nobuyuki Serizawa, Yasushi Katayama
Summary: In this study, electrodeposition of cobalt was investigated in an amide-type ionic liquid under an external magnetic field. The results showed that nanowire-shaped deposits composed of metallic cobalt nanoparticles were formed at 25 degrees Celsius in the presence of the magnetic field.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Zheyong Fan, Petri Hirvonen, Luiz Felipe C. Pereira, Mikko M. Ervasti, Ken R. Elder, Davide Donadio, Ari Harju, Tapio Ala-Nissila
Article
Chemistry, Multidisciplinary
Bohayra Mortazavi, Aurelien Lherbier, Zheyong Fan, Ari Harju, Timon Rabczuk, Jean-Christophe Charlier
Article
Physics, Multidisciplinary
Robert Drost, Teemu Ojanen, Ari Harju, Peter Liljeroth
Article
Computer Science, Interdisciplinary Applications
Zheyong Fan, Ville Vierimaa, Ari Harju
COMPUTER PHYSICS COMMUNICATIONS
(2018)
Article
Multidisciplinary Sciences
Petri Hirvonen, Zheyong Fan, Mikko M. Ervasti, Ari Harju, Ken R. Elder, Tapio Ala-Nissila
SCIENTIFIC REPORTS
(2017)
Review
Physics, Multidisciplinary
Zheyong Fan, Jose H. Garcia, Aron W. Cummings, Jose Eduardo Barrios-Vargas, Michel Panhans, Ari Harju, Frank Ortmann, Stephan Roche
Summary: In recent years, predictive computational modeling has become crucial in studying fundamental electronic, optical, and thermal properties in complex condensed matter. Linear scaling numerical methods have been developed to simulate quantum transport in realistic models, and have been used extensively to explore quantum transport phenomena in disordered media. The review also addresses the trade-off between computational cost and accuracy of different numerical schemes, and demonstrates the usefulness of these methods through examples in the study of transport in disordered materials.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Avijit Kumar, Kaustuv Banerjee, Mikko M. Ervasti, Shawulienu Kezilebieke, Marc Dvorak, Patrick Rinke, Ari Harju, Peter Liljeroth
Summary: The study investigates the formation of a charge-transfer complex of TTF and F(4)TCNQ on the surface of oxygen-intercalated epitaxial graphene on Ir(111), confirming its presence and revealing a correlated ground state. The results suggest the possibility to study correlated ground states in charge-transfer complex monolayers on weakly interacting surfaces.
Article
Radiology, Nuclear Medicine & Medical Imaging
Ann Van Esch, Antti Kulmala, Ronan Rochford, Juha Kauppinen, Ari Harju
Summary: By enhancing the modeling of the multileaf collimator (MLC) in the dose calculation algorithms, the accuracy of dose calculation can be significantly improved. This study demonstrates that the enhanced MLC model effectively resolves discrepancies and provides excellent agreements with measurements.
Article
Radiology, Nuclear Medicine & Medical Imaging
Linda Laakkonen, Zheyong Fan, Ari Harju
Summary: In highly heterogeneous medium, the conventional methods for dose calculation often overestimate the dose in low-density regions or afterwards. To correct this, we propose a method of scaling the total energy released per mass (TERMA) based on density distribution and effective beam size. The corrected convolution method significantly improves accuracy in lung-like tissue and water-like regions after air, while the TERMA correction only adds about 10% computational cost. Due to its accuracy improvement and computational efficiency, the proposed dose calculation method is valuable for inverse treatment planning.
Article
Engineering, Biomedical
Linda Laakkonen, Jouko Lehtomaki, Alexander Cahill, Magdalena Constantin, Antti Kulmala, Ari Harju
Summary: A Monte Carlo model of the Halcyon and Ethos radiotherapy beam was validated, and field-independent phase space (PHSP) files were recorded. The accuracy of the model was confirmed through dose comparisons for square MLC fields and complex field measurements. The produced PHSP files can be used to simulate particle transport through treatment head components accurately.
PHYSICS IN MEDICINE AND BIOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Zheyong Fan, Haikuan Dong, Ari Harju, Tapio Ala-Nissila
Article
Chemistry, Physical
Khatereh Azizi, Petri Hirvonen, Zheyong Fan, Ari Harju, Ken R. Elder, Tapio Ala-Nissila, S. Mehdi Vaez Allaei
Article
Computer Science, Interdisciplinary Applications
Zheyong Fan, Wei Chen, Ville Vierimaa, Ari Harju
COMPUTER PHYSICS COMMUNICATIONS
(2017)
Article
Materials Science, Multidisciplinary
Long Liang, Sebastiano Peotta, Ari Harju, Paivi Torma
Article
Materials Science, Multidisciplinary
Haikuan Dong, Zheyong Fan, Libin Shi, Ari Harju, Tapio Ala-Nissila
