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Related papers: Singlet-Triplet Physics and Shell Filling in Carbo…

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We consider a three-port single-level quantum dot system with one input and two output leads. Instead of considering an empty dot, we study the situations that two input electrons co-tunnel through the quantum dot occupied by one or two dot…

Quantum Physics · Physics 2007-05-23 Chih-Lung Chou

A top-gated single wall carbon nanotube is used to define three coupled quantum dots in series between two electrodes. The additional electron number on each quantum dot is controlled by top-gate voltages allowing for current measurements…

Mesoscale and Nanoscale Physics · Physics 2008-04-23 K. Grove-Rasmussen , H. I. Jørgensen , T. Hayashi , P. E. Lindelof , T. Fujisawa

Quantum phase transitions (QPTs) in qubit systems are known to produce singularities in the entanglement, which could in turn be used to probe the QPT. Current proposals to measure the entanglement are challenging however, because of their…

Mesoscale and Nanoscale Physics · Physics 2013-08-26 Yun-Pil Shim , Sangchul Oh , Jianjia Fei , Xuedong Hu , Mark Friesen

We engineer a system of two strongly confined quantum dots to gain reproducible electrostatic control of the spin at zero magnetic field. Coupling the dots in a tight ring-shaped potential with two tunnel barriers, we demonstrate that an…

We investigate a tunable two-impurity Kondo system in a strongly correlated carbon nanotube double quantum dot, accessing the full range of charge regimes. In the regime where both dots contain an unpaired electron, the system approaches…

Mesoscale and Nanoscale Physics · Physics 2012-10-16 S. J. Chorley , M. R. Galpin , F. W. Jayatilaka , C. G. Smith , D. E. Logan , M. R. Buitelaar

The exchange interaction in a singlet-triplet qubit defined by two-electron states in the double-quantum-dot system ("two-electron singlet-triplet qubit") typically varies monotonically with the exchange interaction and thus carries no…

Mesoscale and Nanoscale Physics · Physics 2022-06-16 Guo Xuan Chan , Xin Wang

We study the dynamics of a single electron spin in a double quantum dot (DQD) and its readout via a quantum point contact (QPC). We model the system microscopically and derive rate equations for the reduced electron density matrix of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Jian-Ping Zhang , Shi-Hua Ouyang , Chi-Hang Lam , J. Q. You

The representation of information within the spins of electrons and nuclei has been powerful in the ongoing development of quantum computers. Although nuclear spins are advantageous as quantum bits (qubits) due to their long coherence…

Spins in gate-defined silicon quantum dots are promising candidates for implementing large-scale quantum computing. To read the spin state of these qubits, the mechanism that has provided the highest fidelity is spin-to-charge conversion…

We describe a hybrid quantum system composed of a micrometer-size carbon nanotube (CNT) longitudinally coupled to a flux qubit. We demonstrate the usefulness of this device for generating high-fidelity nonclassical states of the CNT via…

Quantum Physics · Physics 2017-05-16 Xin Wang , Adam Miranowicz , Hong-Rong Li , Franco Nori

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 study theoretically, two doped Carbon nanotubes connected via a chemically active bond as the basic elementary gate for a recent proposal for qubit teleportation in the solid--state. We show that such a system provides the necessary…

Other Condensed Matter · Physics 2007-05-23 Abraham O. Alaka

Strong electron and spin correlations in a double-quantum-dot (DQD) can give rise to different quantum states. We observe a continuous transition from a Kondo state exhibiting a single-peak Kondo resonance to another exhibiting a double…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. C. Chen , A. M. Chang , M. R. Melloch

Electrons in atoms possess both spin and orbital degrees of freedom. In non-relativistic quantum mechanics, these are independent, resulting in large degeneracies in atomic spectra. However, relativistic effects couple the spin and orbital…

Mesoscale and Nanoscale Physics · Physics 2008-04-07 F. Kuemmeth , S. Ilani , D. C. Ralph , P. L. McEuen

Structural identification of double-walled carbon nanotubes (DWNT) is presented through a robust procedure based on the latest generation of transmission electron microscope, making possible a statistical analysis based on numerous…

We observe two-fold shell filling in the spectra of closed one-dimensional quantum dots formed in single-wall carbon nanotubes. Its signatures include a bimodal distribution of addition energies, correlations in the excitation spectra for…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 David H. Cobden , Jesper Nygard

Spin-orbit coupling is relatively weak for electrons in bulk silicon, but enhanced interactions are reported in nanostructures such as the quantum dots used for spin qubits. These interactions have been attributed to various dissimilar…

Double quantum dots are convenient solid-state platforms to encode quantum information. Two-electron spin states can be conveniently detected and manipulated using strong quantum selection rules based on the Pauli exclusion principle,…

Mesoscale and Nanoscale Physics · Physics 2011-11-22 N. S. Lai , W. H. Lim , C. H. Yang , F. A. Zwanenburg , W. A. Coish , F. Qassemi , A. Morello , A. S. Dzurak

We propose a quantum dot qubit architecture that has an attractive combination of speed and fabrication simplicity. It consists of a double quantum dot with one electron in one dot and two electrons in the other. The qubit itself is a set…

We study the coupling between a singlet-triplet qubit realized in a double quantum dot to a topological qubit realized by spatially well-separated Majorana bound states. We demonstrate that the singlet-triplet qubit can be leveraged for…

Mesoscale and Nanoscale Physics · Physics 2019-04-24 Marko J. Rančić , Silas Hoffman , Constantin Schrade , Jelena Klinovaja , Daniel Loss