Article
Multidisciplinary Sciences
Ryan M. Jock, N. Tobias Jacobson, Martin Rudolph, Daniel R. Ward, Malcolm S. Carroll, Dwight R. Luhman
Summary: This research demonstrates a method for controlling electron spin qubits on a silicon heterointerface through spin-orbit effects, without the need for complex nanofabrication equipment. The method offers high logic gate orthogonality and long qubit coherence time, while enabling fast control. The study also investigates charge noise in a silicon double quantum dot through dynamical decoupling experiments and evaluates qubit frequency drift and low-frequency noise.
NATURE COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Florian N. M. Froning, Leon C. Camenzind, Orson A. H. van der Molen, Ang Li, Erik P. A. M. Bakkers, Dominik M. Zumbuehl, Floris R. Braakman
Summary: Quantum computers promise to execute complex tasks exponentially faster than classical computers, but require fast and selective control of individual qubits while maintaining coherence. Operating a hole spin qubit in a Ge/Si nanowire all-electrically demonstrates the principle of switching between fast control and increased coherence.
NATURE NANOTECHNOLOGY
(2021)
Article
Quantum Science & Technology
Qianfan Chen, Ivar Martin, Liang Jiang, Dafei Jin
Summary: A single electron spin qubit on the surface of solid neon can have an ultralong coherence time, making it a promising new spin qubit system. The estimated coherence time on commercially available purified neon can reach 81 seconds.
QUANTUM SCIENCE AND TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
David Curie, Jaron T. Krogel, Lukas Cavar, Abhishek Solanki, Pramey Upadhyaya, Tongcang Li, Yun-Yi Pai, Michael Chilcote, Vasudevan Iyer, Alexander Puretzky, Ilia Ivanov, Mao-Hua Du, Fernando Reboredo, Benjamin Lawrie
Summary: This study reveals the effect of strain on the negatively charged boron vacancy color center (VB-) in hexagonal boron nitride (hBN) through correlative cathodoluminescence and photoluminescence microscopies. The results show that strong localized enhancement and redshifting of the VB- luminescence can be observed at creases, consistent with density functional theory calculations.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Multidisciplinary
Kazuyuki Kuroyama, Sadashige Matsuo, Jo Muramoto, Shunsuke Yabunaka, Sascha R. Valentin, Arne Ludwig, Andreas D. Wieck, Yasuhiro Tokura, Seigo Tarucha
Summary: We report experimental observations of charge-spin cooperative dynamics of two-electron states in a GaAs double quantum dot located in a nonequilibrium phonon environment. The spin-flip rate of a single electron is significantly enhanced when the phonon energy exceeds the lowest excitation energy in the quantum dot. In addition, the spatial gradient of phonon density between the dots leads to a higher probability of parallel spin states than antiparallel ones.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
V. N. Mantsevich, D. S. Smirnov
Summary: We propose a mechanism for current-induced spin polarization in semiconductor heterostructures based on the complex structure of the valence band. By coupling a quantum dot and quantum wire with heavy holes, an exponentially small bias can create 100% spin polarization in the quantum dot, in contrast to traditional mechanisms based on linear momentum spin-orbit coupling. This effect is related to the formation of chiral quasi bound states and the spin-dependent tunneling of holes.
NANOSCALE HORIZONS
(2022)
Article
Optics
Jingyi Fan, Shengshi Pang
Summary: In this work, we investigate the role of finite bath dimension in the Markovianity of quantum dynamics by considering a simple but nontrivial model. We find that the dynamics of the central spin transits from non-Markovian to Markovian as the number of the bath spins increases. The non-Markovianity is characterized by the information backflow from the bath to the system in terms of the trace distance of the system states. We derive the time evolution of the trace distance analytically, and find periodic collapse-revival patterns in the information flow.
Article
Chemistry, Multidisciplinary
Ignacio Gimeno, Ainhoa Urtizberea, Juan Roman-Roche, David Zueco, Agustin Camon, Pablo J. Alonso, Olivier Roubeau, Fernando Luis
Summary: Through a series of experiments, vanadyl porphyrin molecules show the potential to encode multiple qubits and exhibit electronuclear entanglement under certain conditions. These findings expand the range of chemically designed systems capable of implementing non-trivial quantum functionalities.
Article
Materials Science, Multidisciplinary
Ada Warren, Utkan Gungordu, J. P. Kestner, Edwin Barnes, Sophia E. Economou
Summary: Significant experimental progress has been made in single-electron silicon spin qubits, with the proposal of new quantum gate iSWAP but fidelity issues. A photon-mediated cross-resonance gate has been introduced, eliminating the need for resonance tuning, along with gate sequences to suppress errors.
Article
Physics, Applied
Xiaodong Yang, Yunrui Ge, Bo Zhang, Jun Li
Summary: This study investigates the combination of dynamical decoupling and robust optimal control for high-fidelity control of quantum systems. By using robust optimal control to find robust control pulses and incorporating them into dynamical decoupling sequences, a remarkable improvement in robustness against multiple error channels is achieved.
PHYSICAL REVIEW APPLIED
(2022)
Article
Optics
Niels Heermeier, Tobias Heuser, Jan Grosse, Natalie Jung, Arsenty Kaganskiy, Markus Lindemann, Nils C. Gerhardt, Martin R. Hofmann, Stephan Reitzenstein
Summary: Spin-controlled lasers and high-beta quantum dot micropillar lasers are two fascinating photonic devices with potential applications. The experimental and predicted polarization oscillation frequencies of spin-laser effects are presented, demonstrating the possibility of developing more compact, faster, and more energy-efficient spin-lasers.
LASER & PHOTONICS REVIEWS
(2022)
Article
Physics, Multidisciplinary
Emma Rosenfeld, Ralf Riedinger, Jan Gieseler, Martin Schuetz, Mikhail D. Lukin
Summary: In the lab, scientists have proposed a scheme that uses a hot mechanical oscillator to entangle distant spin qubits, showing that it is feasible with realistic parameters. They found that high-fidelity entanglement can be achieved at low and ambient temperatures, opening up new possibilities for quantum processing of solid-state spin qubits.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Qingqian Wang, Hongmei Zhu, Yangzhi Tan, Junjie Hao, Taikang Ye, Haodong Tang, Zhaojin Wang, Jingrui Ma, Jiayun Sun, Tianqi Zhang, Fankai Zheng, Wenda Zhang, Hoi Wai Choi, Wallace C. H. Choy, Dan Wu, Xiao Wei Sun, Kai Wang
Summary: Chiral-induced spin selectivity (CISS) effect provides an innovative approach to spintronics and quantum-based devices for chiral materials, and has the potential to operate under room temperature and zero applied magnetic field. This study reports spin-QLEDs enabled by 2D chiral perovskites as CISS layer, and discovers the regulation pattern of chirality and thickness affecting the circularly polarized electroluminescence (CP-EL) emission.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Josephine Dias, Christopher W. Waechtler, Victor M. Bastidas, Kae Nemoto, William J. Munro
Summary: The transfer of energy through a network of nodes is crucial to nature and technology. By replacing traditional channels with collective environments, energy can be efficiently transferred from one node to another even at zero temperature, showing potential for future quantum technologies.
Article
Chemistry, Multidisciplinary
Daria D. Blach, Victoria A. Lumsargis, Daniel E. Clark, Chern Chuang, Kang Wang, Letian Dou, Richard D. Schaller, Jianshu Cao, Christina W. Li, Libai Huang
Summary: This study investigates the coherence of excitons in perovskite quantum dot solids by measuring the temperature-dependent photoluminescence line width and lifetime. The results show that excitons can coherently spread over three quantum dots in a superlattice, leading to superradiant emission. However, scattering from optical phonons causes the loss of coherence at higher temperatures, resulting in exciton localization to a single quantum dot. Static disorder and defects limit exciton coherence at low temperatures.
Article
Optics
C. E. Whittaker, T. Dowling, A. Nalitov, A. Yulin, B. Royall, E. Clarke, M. S. Skolnick, I. A. Shelykh, D. N. Krizhanovskii
Summary: An experimental synthetic non-Abelian gauge field for photons was successfully realized in a honeycomb microcavity lattice, revealing its symmetry in the optical spin Hall effect and paving the way for photon manipulation via spin on a chip. The unique fine structure of eigenstates around Dirac points in photonic graphene made of coupled polaritonic microcavities was demonstrated, showing the formation of a Dresselhaus-like effective magnetic field that can be mapped to a non-Abelian gauge field.
Article
Physics, Multidisciplinary
D. M. Jackson, D. A. Gangloff, J. H. Bodey, L. Zaporski, C. Bachorz, E. Clarke, M. Hugues, C. Le Gall, M. Atature
Summary: The coupling between a semiconductor nuclear spin ensemble and an electron-spin quantum dot enables the detection of a single excitation with parts-per-million accuracy. This breakthrough in quantum sensing allows for investigating emergent quantum phenomena and potential applications in probing engineered quantum states of the ensemble.
Article
Quantum Science & Technology
George Gillard, Ian M. Griffiths, Gautham Ragunathan, Ata Ulhaq, Callum McEwan, Edmund Clarke, Evgeny A. Chekhovich
Summary: By adjusting the tunneling coupling range, including the limit of isolated quantum dots, we unravel the contributions of spin relaxation mechanisms in quantum dot spins. The experimental results show that while reducing tunneling can extend the lifetime of electron spin qubits, it can also decrease the fidelity of optical spin initialization.
NPJ QUANTUM INFORMATION
(2021)
Article
Physics, Multidisciplinary
Dorian A. Gangloff, Leon Zaporski, Jonathan H. Bodey, Clara Bachorz, Daniel M. Jackson, Gabriel Ethier-Majcher, Constantin Lang, Edmund Clarke, Maxime Hugues, Claire Le Gall, Mete Atature
Summary: The study proposes a method to reconstruct the nuclear spin ensemble by exploiting its response to collective spin excitations, demonstrating that the ensemble is in a non-thermal, correlated state with a significant deviation from the classical prediction. The reconstructed species-resolved polarizations suggest the presence of inter-particle coherences and serve as entanglement witnesses for the formation of a dark many-body state within the ensemble.
Article
Physics, Applied
Feng Li, Yiming Li, L. Giriunas, M. Sich, D. D. Solnyshkov, G. Malpuech, A. A. P. Trichet, J. M. Smith, E. Clarke, M. S. Skolnick, D. N. Krizhanovskii
Summary: In this study, a tunable open-access microcavity was established to achieve polariton condensation by controlling the light-matter coupling strength through nanopositioners. The experimental results showed that the lowest condensation threshold always occurred at a fixed energy trap depth for different coupling strengths.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Optics
Osamu Kojima, Yuki Tarui, Takashi Kita, Avan Majeed, Pavlo Ivanov, Edmund Clarke, Richard A. Hogg
Summary: This study reports an increase in the intensity of terahertz (THz) waves generated by differential frequency mixing using commercial permanent magnets. When a weak magnetic field is applied, the THz-wave intensity increases due to excitons, while a strong magnetic field causes a decrease in intensity. The calculations suggest that the increase is due to electron-hole separation caused by the Lorentz force, and carrier acceleration plays an important role in enhancing the intensity.
Article
Engineering, Electrical & Electronic
Ye Cao, Tarick Osman, Edmund Clarke, Pallavi Kisan Patil, Jo Shien Ng, Chee Hing Tan
Summary: Avalanche photodiodes (APDs) made with AlGaAsSb exhibit excellent noise characteristics. The SAM-APD incorporating GaAsSb absorption region and AlGaAsSb avalanche region shows a cutoff wavelength of 1.70 μm and a responsivity of 0.39 A/W at 1.55 μm wavelength. The temperature dependence of the breakdown voltage is significantly smaller compared to InP and InAlAs SAM-APDs.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
George Gillard, Edmund Clarke, Evgeny A. Chekhovich
Summary: This study demonstrates millisecond coherence times for a nuclear spin ensemble coupled to a single electron spin qubit in a semiconductor quantum dot, providing new understanding of the many-body coherence in central spin systems required for the development of electron-nuclear spin qubits.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Daniel M. Jackson, Urs Haeusler, Leon Zaporski, Jonathan H. Bodey, Noah Shofer, Edmund Clarke, Maxime Hugues, Mete Atature, Claire Le Gall, Dorian A. Gangloff
Summary: This study presents a feedback algorithm applied to a quantum system that stabilizes the collective state from a maximum entropy state to single quantum fluctuations. Experimental results demonstrate the robustness of this feedback algorithm on highly inhomogeneous nuclear-spin ensemble and the ability to tailor nontrivial nuclear-spin distributions.
Review
Nanoscience & Nanotechnology
Alejandro R. -P. Montblanch, Matteo Barbone, Igor Aharonovich, Mete Atature, Andrea C. Ferrari
Summary: This review highlights the role of transition metal dichalcogenides, hexagonal boron nitride, and stacked heterostructures in various quantum technology applications. Layered materials have attractive properties for quantum technologies and have already shown potential in scalable components such as light sources, photon detectors, and nanoscale sensors. The review discusses the opportunities and challenges faced by these materials in the field of quantum technologies, particularly in applications relying on light-matter interfaces.
NATURE NANOTECHNOLOGY
(2023)
Article
Quantum Science & Technology
Hamidreza Siampour, Christopher O'Rourke, Alistair J. Brash, Maxim N. Makhonin, Rene Dost, Dominic J. Hallett, Edmund Clarke, Pallavi K. Patil, Maurice S. Skolnick, A. Mark Fox
Summary: Quantum states of light and matter can be manipulated on the nanoscale to aid the implementation of scalable photonic quantum technologies. A nanophotonic waveguide platform with embedded quantum dots (QDs) was demonstrated, allowing for Purcell-enhanced emission and strong chiral coupling. Record-large radiative decay rate and Purcell enhancement were achieved through electric-field tuning and quasi-resonant excitation. The results show promising prospects for using QDs in scalable implementations of on-chip spin-photonics relying on chiral quantum optics.
NPJ QUANTUM INFORMATION
(2023)
Article
Chemistry, Multidisciplinary
Roman Hartmann, Michael Hogen, Daphne Lignon, Anthony K. C. Tan, Mario Amado, Sami El-Khatib, Mehmet Egilmez, Bhaskar Das, Chris Leighton, Mete Atature, Elke Scheer, Angelo Di Bernardo
Summary: The coexistence of different properties in NiS2 nanoflakes, such as antiferromagnetic and weak ferromagnetic orders, along with surface metallicity, leads to strongly field-asymmetric magnetotransport features at low temperatures. These features are related to exchange-bias-type effects between ferromagnetic and antiferromagnetic regions forming near step edges at the nanoflake surface, which can be characterized using nitrogen vacancy magnetometry. The findings suggest that NiS2 nanoflakes have potential applications in van der Waals heterostructures for low-temperature spintronics and superconducting spintronics.
Article
Optics
C. E. Whittaker, D. R. Gulevich, D. Bieganska, B. Royall, E. Clarke, M. S. Skolnick, I. A. Shelykh, D. N. Krizhanovskii
Summary: The study investigates the magneto-optical response of exciton polaritons in p-orbital flat bands in a two-dimensional Lieb lattice of semiconductor microcavity pillars. It was found that the external magnetic field can be used to tune the flat-band states and spin population imbalance can be induced by circularly polarized pumping at high excitation density. Additionally, the interplay between the symmetry of orbital wave function, photonic spin-orbit coupling, and Zeeman splittings leads to the formation of real-space flat-band patterns with tilted orbital wave functions.
