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Related papers: Single, double, and triple quantum dots in Ge/Si n…

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Hole spin qubits are frontrunner platforms for scalable quantum computers, but state-of-the-art devices suffer from noise originating from the hyperfine interactions with nuclear defects. We show that these interactions have a highly…

Mesoscale and Nanoscale Physics · Physics 2021-11-04 Stefano Bosco , Daniel Loss

Single nuclear spins in silicon are a promising resource for quantum technologies due to their long coherence times and excellent control fidelities. Qubits and qudits have been encoded on donor nuclei, with successful demonstrations of…

The epitaxial growth of germanium on silicon leads to the self-assembly of SiGe nanocrystals via a process that allows the size, composition and position of the nanocrystals to be controlled. This level of control, combined with an inherent…

Mesoscale and Nanoscale Physics · Physics 2010-05-12 G. Katsaros , P. Spathis , M. Stoffel , F. Fournel , M. Mongillo , V. Bouchiat , F. Lefloch , A. Rastelli , O. G. Schmidt , S. De Franceschi

Operation speed and coherence time are two core measures for the viability of a qubit. Strong spin-orbit interaction (SOI) and relatively weak hyperfine interaction make holes in germanium (Ge) intriguing candidates for spin qubits with…

We consider a model of two interacting always-on, exchange-only qubits for which controlled phase ($CPHASE$), controlled NOT ($CNOT$), quantum Fourier transform ($QFT$) and $SWAP$ operations can be implemented only in a few electrical…

Mesoscale and Nanoscale Physics · Physics 2018-05-09 Jakub Łuczak , Bogdan R. Bułka

Individual spin defects in solids are promising building blocks for quantum technologies, but their deterministic creation, individual addressability, and operation near surfaces remain major challenges. Two-dimensional materials provide an…

The spin states of single electrons in gate-defined quantum dots satisfy crucial requirements for a practical quantum computer. These include extremely long coherence times, high-fidelity quantum operation, and the ability to shuttle…

We demonstrate a reconfigurable quantum dot gate architecture that incorporates two interchangeable transport channels. One channel is used to form quantum dots and the other is used for charge sensing. The quantum dot transport channel can…

Mesoscale and Nanoscale Physics · Physics 2015-06-29 D. M. Zajac , T. M. Hazard , X. Mi , K. Wang , J. R. Petta

Electron spins in semiconductor quantum dots are good candidates of quantum bits for quantum information processing. Basic operations of the qubit have been realized in recent years: initialization, manipulation of single spins, two qubit…

The current work explores a geometrically engineered dual gate GaAs nanowire FET with state of the art miniaturized dimensions for high performance charge qubit operation at room temperature. Relevant gate voltages in such device can create…

Mesoscale and Nanoscale Physics · Physics 2023-04-24 Nilayan Paul , Basudev Nag Chowdhury , Sanatan Chattopadhyay

We describe a planar silicon metal-oxide-semiconductor (MOS) based single hole transistor, which is compatible with conventional Si CMOS fabrication. A multi-layer gate design gives independent control of the carrier density in the dot and…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 R. Li , F. E. Hudson , A. S. Dzurak , A. R. Hamilton

We report integrated charge sensing measurements on a Si/SiGe double quantum dot. The quantum dot is shown to be tunable from a single, large dot to a well-isolated double dot. Charge sensing measurements enable the extraction of the tunnel…

We demonstrate fully tunable single and double quantum dots in a one-dimensional hole system based on undoped Ge/Si core-shell nanowire heterostructures. The local hole density along the nanowire is controlled by applying voltages to five…

Mesoscale and Nanoscale Physics · Physics 2007-06-21 S. Roddaro , A. Fuhrer , C. Fasth , L. Samuelson , J. Xiang , C. M. Lieber

Spin qubits are very valuable and scalable candidates in the area of quantum computation and simulation applications. In the last decades, they have been deeply investigated from a theoretical point of view and realized on the scale of few…

Quantum Physics · Physics 2019-11-14 E. Ferraro , M. De Michielis

We present a theory of electronic properties and the spin blockade phenomena in a gated linear triple quantum dot. Quadruple points where four different charge configurations are on resonance, particularly involving (1,1,1) configuration,…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Chang-Yu Hsieh , Yun-Pil Shim , Pawel Hawrylak

Coupled colloidal quantum dot molecules composed of two fused CdSe/CdS core/shell sphere monomers were recently presented. Upon fusion, the potential energy landscape is changing into two quantum dots separated by a pre-tuned potential…

Mesoscale and Nanoscale Physics · Physics 2019-12-11 Yossef E. Panfil , Doaa Shamalia , Jiabin Cui , Somnath Koley , Uri Banin

Two tunnel-coupled few-electron quantum dots were fabricated in a GaAs/AlGaAs quantum well. The absolute number of electrons in each dot could be determined from finite bias Coulomb blockade measurements and gate voltage scans of the dots,…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 I. H. Chan , P. Fallahi , A. Vidan , R. M. Westervelt , M. Hanson , A. C. Gossard

We realize a superconductor-coupled quantum dot (QD) in an InSb nanosheet, a 2D platform promising for studies of topological superconductivity. The device consists of a superconductor-QD-superconductor junction, where a bottom bilayer gate…

Superconductivity · Physics 2026-02-10 Xingjun Wu , Ji-Yin Wang , Haitian Su , Han Gao , Shili Yan , Dong Pan , Jianhua Zhao , Po Zhang , H. Q. Xu

We observe the low-lying excitations of a molecular dimer formed by two electrons in a GaAs semiconductor quantum dot in which the number of confined electrons is tuned by optical illumination. By employing inelastic light scattering we…

Mesoscale and Nanoscale Physics · Physics 2010-06-16 Achintya Singha , Vittorio Pellegrini , Aron Pinczuk , Loren N. Pfeiffer , Ken W. West , Massimo Rontani

We demonstrate an efficient method to engineer the quantum confinement in a system of two quantum dots grown in a vertical stack. We achieve this by using materials with a different lattice constant for the growth of the outer and inner…

Mesoscale and Nanoscale Physics · Physics 2015-02-13 Ł. Kłopotowski , P. Wojnar , S. Kret , M. Parlińska-Wojtan , K. Fronc , G. Karczewski , T. Wojtowicz