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Silicon spin qubits in gate-defined quantum dots leverage established semiconductor infrastructure and offer a scalable path toward transformative quantum technologies. Holes spins in silicon offer compact all-electrical control, whilst…

A crucial requirement for scalable quantum-information processing is the realization of multiple-qubit quantum gates. Universal multiple-qubit gates can be implemented by a set of universal single qubit gates and any one kind of two-qubit…

Quantum Physics · Physics 2014-11-20 Hai-Ou Li , Gang Cao , Guo-Dong Yu , Ming Xiao , Guang-Can Guo , Hong-Wen Jiang , Guo-Ping Guo

We present a theory of quantum circuits based on logical qubits encoded in chirality of electron spin complexes in lateral gated semiconductor triple quantum dot molecules with one electron spin in each dot. Using microscopic Hamiltonian we…

Strongly Correlated Electrons · Physics 2015-05-18 Chang-Yu Hsieh , Pawel Hawrylak

The probabilistic nature of single-photon sources and photon-photon interactions encourages encoding as much quantum information as possible in every photon for the purpose of photonic quantum information processing. Here, by encoding…

Nuclear spins were among the first physical platforms to be considered for quantum information processing, because of their exceptional quantum coherence and atomic-scale footprint. However, their full potential for quantum computing has…

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 show that two electrons confined in a square semiconductor quantum dot have two isolated low-lying energy eigenstates, which have the potential to form the basis of scalable computing elements (qubits). Initialisation, one-qubit and…

Quantum Physics · Physics 2009-11-07 J. H. Jefferson , M. Fearn , D. L. J. Tipton , T. P. Spiller

The universal quantum computation is obtained when there exists asymmetric anisotropic exchange between electron spins in coupled semiconductor quantum dots. The asymmetric Heisenberg model can be transformed into the isotropic model…

Quantum Physics · Physics 2009-11-13 Xiang Hao , Shiqun Zhu

Interacting fermions on a lattice can develop strong quantum correlations, which lie at the heart of the classical intractability of many exotic phases of matter. Seminal efforts are underway in the control of artificial quantum systems,…

Mesoscale and Nanoscale Physics · Physics 2017-08-16 T. Hensgens , T. Fujita , L. Janssen , Xiao Li , C. J. Van Diepen , C. Reichl , W. Wegscheider , S. Das Sarma , L. M. K. Vandersypen

Suppressing errors is the central challenge for useful quantum computing, requiring quantum error correction for large-scale processing. However, the overhead in the realization of error-corrected ``logical'' qubits, where information is…

In this paper, we present the experimental realization of multi-qubit gates $% \Lambda_n(not) $ in macroscopic ensemble of three-qubit and four-qubit molecules. Instead of depending heavily on the two-bit universal gate, which served as the…

Quantum Physics · Physics 2009-11-06 J. F. Du , M. J. Shi , J. H. Wu , X. Y. Zhou , R. D. Han

A quantum computer based on an asymmetric coupled dot system has been proposed and shown to operate as the controlled-NOT-gate. The basic idea is (1) the electron is localized in one of the asymmetric coupled dots. (2)The electron transfer…

Quantum Physics · Physics 2008-12-18 Tetsufumi Tanamoto

Semiconductor spin qubits offer a unique opportunity for scalable quantum computation by leveraging classical transistor technology. Hole spin qubits benefit from fast all-electrical qubit control and sweet spots to counteract charge and…

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…

Quantum dot hybrid qubits formed from three electrons in double quantum dots represent a promising compromise between high speed and simple fabrication for solid state implementations of single qubit and two qubits quantum logic ports. We…

Quantum Physics · Physics 2018-09-05 E. Ferraro , M. De Michielis , G. Mazzeo , M. Fanciulli , E. Prati

Silicon, the main constituent of microprocessor chips, is emerging as a promising material for the realization of future quantum processors. Leveraging its well-established complementary metal-oxide-semiconductor (CMOS) technology would be…

Mesoscale and Nanoscale Physics · Physics 2016-12-21 R. Maurand , X. Jehl , D. Kotekar Patil , A. Corna , H. Bohuslavskyi , R. Laviéville , L. Hutin , S. Barraud , M. Vinet , M. Sanquer , S. De Franceschi

An anomalous energy splitting of spin triplet states at zero magnetic field has recently been measured in germanium quantum dots. This zero-field splitting could crucially alter the coupling between tunnel-coupled quantum dots, the basic…

Mesoscale and Nanoscale Physics · Physics 2022-09-21 Bence Hetényi , Stefano Bosco , Daniel Loss

Spin qubits in silicon-MOS (SiMOS) quantum dots have recently demonstrated compatibility with existing industry standard CMOS fabrication techniques. These devices have routinely achieved single- and two-qubit gate fidelities above 99% and…

Many promising ideas for quantum computing demand the experimental ability to directly switch 'on' and 'off' a physical coupling between the component qubits. This is typically the key difficulty in implementation, and precludes quantum…

Quantum Physics · Physics 2009-11-07 Simon C. Benjamin , Sougato Bose

We propose a method for implementation of a quantum computer using artificial molecules. The artificial molecule consists of two coupled quantum dots stacked along z direction and one single electron. One-qubit and two-qubit gates are…

Quantum Physics · Physics 2009-10-31 Nan-Jian Wu , M. Kamada , A. Natori , H. Yasunaga