Article
Quantum Science & Technology
Michael Berger, Jamal Berakdar
Summary: Quantum states of systems with classical chaotic dynamics can be scarred, and this study demonstrates how the scarred state can be imaged to a region that does not support scarring. This phantom scar has a significant impact on the spin-dependent system dynamics, as shown by explicit calculations for fidelity and correlation functions. Numerical simulations and analysis for the spin-dependent electron dynamics in semiconductor-based double quantum dots provide insights into the coherent phenomenon of scarring and its localization properties in a narrow spectral window.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Optics
J. D. Arias Espinoza, M. Mazzanti, K. Fouka, R. X. Schuessler, Z. Wu, P. Corboz, R. Gerritsma, A. Safavi-Naini
Summary: The proposed method uses optical tweezers to engineer the sound-wave spectrum of trapped ion crystals, allowing for tuning of interactions and connectivity beyond current setups. Demonstrated feasibility of generating target spin-spin interaction patterns in both one- and two-dimensional crystals using realistic tweezer settings and experimentally relevant trap parameters. This approach advances quantum simulation in trapped-ion platforms by enabling realization of a broader family of quantum spin Hamiltonians.
Article
Multidisciplinary Sciences
J. Yoneda, W. Huang, M. Feng, C. H. Yang, K. W. Chan, T. Tanttu, W. Gilbert, R. C. C. Leon, F. E. Hudson, K. M. Itoh, A. Morello, S. D. Bartlett, A. Laucht, A. Saraiva, A. S. Dzurak
Summary: The article demonstrates high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon, with a reported polarization transfer fidelity of 99.97% and an average coherent transfer fidelity of 99.4%. The results suggest that this method can reduce the cost of fault-tolerant quantum processors and provide key elements for high-fidelity, on-chip quantum information distribution.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Ekrem Taha Guldeste, Ceyhun Bulutay
Summary: This work introduces the synchrosqueezed wavelet transform to study the dipolar fluctuations of nuclear spins in a diamond crystal structure. The dynamics of the spin ensemble is analyzed based on zero-, single-, and double-quantum transitions. The study reveals the modulation of Overhauser field fluctuations and the presence of different beating patterns in the nuclear spin noise, providing spatial information about the spin clusters surrounding the central spin. Additionally, denoising techniques in the wavelet domain are demonstrated to effectively remove noise in the scalograms.
Article
Chemistry, Physical
Zhen Wu, Yuanyuan Zhang, Rongrong Hu, Meizhen Jiang, Pan Liang, Qing Yang, Li Deng, Tianqing Jia, Zhenrong Sun, Donghai Feng
Summary: The electron spin dynamics in CdSe quantum dots with hole acceptors were investigated using time-resolved ellipticity spectroscopy. Two types of hole acceptors, Li[Et3BH] and 1-octanethiol, resulted in distinctly different electron spin dynamics. Differences were observed in electron g factors, spin dephasing/relaxation times, and mechanisms.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Nanoscience & Nanotechnology
M. Milivojevic
Summary: The study explores the possibility of determining the Rashba spin-orbit coupling strength in InSb nanowire quantum dots by measuring the magnetic susceptibility of the two-electron system in a double quantum dot. It is found that the magnetic susceptibility reaches a maximal value when the spin-orbit and magnetic field are parallel/antiparallel, which can be used to extract the value of the Rashba parameter.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Physics, Applied
S. Yamamoto, R. Kaji, H. Sasakura, S. Adachi
Summary: Experimental observations on nuclear spin polarization in quantum dots reveal that under a longitudinal magnetic field, there are three stable branches of nuclear spin polarization, contrary to the previous belief of at most two stable branches. The incorporation of electron spin relaxation due to nuclear spin fluctuation allows for the reproduction of observed features of nuclear spin polarization and electron spin polarization.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Mohsen Yarmohammadi, Katrin Bolsmann, Yvonne Ribbeheger, Timo Graesser, Goetz S. Uhrig
Summary: The central spin model is highly applicable to describe small quantum systems in contact with a bath of spins. A large bath of quantum spins can be represented by quantum harmonic oscillators, but the resulting model is still challenging to solve. This study examines the effectiveness of a semi-classical truncated Wigner approximation compared to other approximate and exact methods, finding that it works well for short times but deviates for long times. The applicability of semi-classical approaches depends strongly on the variables used to formulate the model.
Article
Chemistry, Analytical
Rong Liao, Si Dai, Biao Liu, Wenfang Deng, Yueming Tan, Qingji Xie
Summary: A novel strategy for photocurrent polarity switchable sensing is reported in this study by regulating electrostatic interactions between two semiconductor photoactive materials. The method achieves low detection limits and a wide linear detection range in the detection of HAase activity, providing a new and effective approach for photocurrent polarity switching and HAase activity detection.
ANALYTICAL CHEMISTRY
(2023)
Article
Physics, Multidisciplinary
Xin-Lei Hei, Peng-Bo Li, Xue-Feng Pan, Franco Nori
Summary: This study predicts a tripartite coupling mechanism in a hybrid setup consisting of a single nitrogen-vacancy (NV) center and a micromagnet, enabling direct and strong tripartite interactions among single NV spins, magnons, and phonons. By modulating the relative motion between the NV center and the micromagnet, a tunable and strong spin-magnon-phonon coupling at the single quantum level can be achieved. This opens up possibilities for quantum spin-magnonics-mechanics and paves the way for general applications in quantum simulations and information processing.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Mohammad Haidar, Vladimir I. Korobov, Laurent Hilico, Jean -Philippe Karr
Summary: This study focuses on higher-order corrections to the spin-orbit and spin-spin tensor interactions in hydrogen molecular ions. The authors derive the m alpha 7ln(alpha)-order radiative correction using the NRQED framework. Complete numerical calculations, including the m alpha 6-order relativistic correction, are presented for the case of H-2(+). The theoretical uncertainty is significantly reduced compared to the Breit-Pauli level, to a few ppm. The results are also compared with available rf spectroscopy data.
Article
Physics, Multidisciplinary
Or Katz, Marko Cetina, Christopher Monroe
Summary: We present a simple protocol for generating N-body entangling interactions between trapped atomic ion qubits in a single step. By utilizing qubit state-dependent squeezing operations and displacement forces on the collective atomic motion, full N-body interactions can be achieved. This N-body gate operation allows for the single-step implementation of a family of N-bit gate operations, including the powerful N-Toffoli gate.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Juno Kim, Yuanze Xu, David Bain, Mingxing Li, Mircea Cotlet, Qiuming Yu, Andrew J. Musser
Summary: By chemically tuning the interactions between perovskite quantum dots (QDs), researchers have discovered that it is possible to control the type and function of polarons. This manipulation not only enhances the spatial diffusion and lifetime of polarons, but also provides design principles for QD-based materials and unravels polaronic species in hybrid perovskite materials.
Article
Physics, Multidisciplinary
Lea -Marina Steinert, Philip Osterholz, Robin Eberhard, Lorenzo Festa, Nikolaus Lorenz, Zaijun Chen, Arno Trautmann, Christian Gross
Summary: Researchers have achieved spatially tunable interactions in analog quantum simulators by manipulating Rydberg atoms, expanding the capabilities of these simulators.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
A. Hijano, E. J. Rodriguez, D. Bercioux, D. Frustaglia
Summary: This work investigates the response of spin carriers to effective field textures in curved one-dimensional interferometric circuits, finding that the interplay between Rashba and Dresselhaus spin-orbit interactions and circuit geometry modifies the geometric characteristics of spinors, resulting in the localization of electronic wave function and suppression of quantum conductance.
COMMUNICATIONS PHYSICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Zheyong Fan, Ville Vierimaa, Ari Harju
COMPUTER PHYSICS COMMUNICATIONS
(2018)
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
Zheyong Fan, Andreas Uppstu, Ari Harju
Article
Materials Science, Multidisciplinary
Zheyong Fan, Luiz Felipe C. Pereira, Petri Hirvonen, Mikko M. Ervasti, Ken R. Elder, Davide Donadio, Tapio Ala-Nissila, Ari Harju
Article
Chemistry, Multidisciplinary
Avijit Kumar, Kaustuv Banerjee, Marc Dvorak, Fabian Schulz, Ari Harju, Patrick Rinke, Peter Liljeroth
Article
Materials Science, Multidisciplinary
Long Liang, Tuomas I. Vanhala, Sebastiano Peotta, Topi Siro, Ari Harju, Paivi Torma
Article
Materials Science, Multidisciplinary
Haikuan Dong, Zheyong Fan, Libin Shi, Ari Harju, Tapio Ala-Nissila
