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Related papers: Tomography scheme for two spin-1/2 qubits in a dou…

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The scalability and power of quantum computing architectures depend critically on high-fidelity operations and robust and flexible qubit connectivity. In this respect, mobile qubits are particularly attractive as they enable dynamic and…

Achieving high-fidelity two-qubit gates is crucial for spin qubits in silicon double quantum dots. However, the two-qubit gates in experiments are easily suffered from charge noise, which is still a key challenge. Geometric gates which…

Quantum Physics · Physics 2024-09-04 Yong-Yang Lu , Kejin Wei , Chengxian Zhang

We demonstrate experimentally a read-out method that distinguishes between two-electron spin states in a quantum dot. This scheme combines the advantages of the two existing mechanisms for spin-to-charge conversion with single-shot charge…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 T. Meunier , K-J. Tielrooij , I. T. Vink , F. H. L. Koppens , H. P. Tranitz , W. Wegscheider , L. P. Kouwenhoven , L. M. K. Vandersypen

Silicon spin qubits form one of the leading platforms for quantum computation. As with any qubit implementation, a crucial requirement is the ability to measure individual quantum states rapidly and with high fidelity. As the signal from a…

Mesoscale and Nanoscale Physics · Physics 2019-07-10 G. Zheng , N. Samkharadze , M. L. Noordam , N. Kalhor , D. Brousse , A. Sammak , G. Scappucci , L. M. K. Vandersypen

Single-qubit measurements are typically insufficient for inferring arbitrary quantum states of a multi-qubit system. We show that if the system can be fully controlled by driving a single qubit, then utilizing a local random pulse is almost…

Quantum Physics · Physics 2020-01-14 Pengcheng Yang , Min Yu , Ralf Betzholz , Christian Arenz , Jianming Cai

We identify a novel mechanism to read out a single solid-state electron spin using an all-electrical spin-to-charge conversion in a closed system. Our scheme uses three donors and two electron spins, one spin is the qubit, the other is a…

Other Condensed Matter · Physics 2007-05-23 Andrew D. Greentree , A. R. Hamilton , Lloyd C. L. Hollenberg , R. G. Clark

Raman qubits, represented by two ground or metastable quantum states coupled via an intermediate state, hold some advantages over directly coupled qubits, most notably much longer radiative lifetimes, shorter gate duration and lower…

Quantum Physics · Physics 2023-10-09 Stancho G. Stanchev , Nikolay V. Vitanov

Recent achievements in the field of gate defined semiconductor quantum dots reinforce the concept of a spin-based quantum computer consisting of nodes of locally connected qubits which communicate with each other via superconducting circuit…

Mesoscale and Nanoscale Physics · Physics 2020-05-28 Jorge Cayao , Mónica Benito , Guido Burkard

Quantum state tomography (QST) represents an essential tool for the characterization, verification, and validation (QCVV) of quantum processors. Only for a few idealized scenarios, there are analytic results for the optimal measurement set…

Quantum Physics · Physics 2022-12-27 Violeta N. Ivanova-Rohling , Niklas Rohling , Guido Burkard

To realize large-scale quantum information processes, an ideal scheme for two-qubit operations should enable diverse operations with given hardware and physical interaction. However, for spin qubits in semiconductor quantum dots, the common…

We propose a deterministic and scalable scheme to construct a two-qubit controlled-NOT (CNOT) gate and realize entanglement swapping between photonic qubits using a quantum-dot (QD) spin in a double-sided optical microcavity. The scheme is…

Quantum Physics · Physics 2015-06-17 Hong-Fu Wang , Ai-Dong Zhu , Shou Zhang , Kyu-Hwang Yeon

Integration of electron spin resonance (ESR) in a scanning tunneling microscope (STM) has enabled an all-electrical control of atomic and molecular spins on solid surfaces with atomic-scale precision and energy resolution beyond thermal…

Mesoscale and Nanoscale Physics · Physics 2025-09-03 Deung-Jang Choi , Soo-hyon Phark , Andreas J. Heinrich , Nicolás Lorente

We report on the realization of a few-electron double quantum dot defined in a two-dimensional electron gas by means of surface gates on top of a GaAs/AlGaAs heterostructure. Two quantum point contacts (QPCs) are placed in the vicinity of…

Electron spin qubits in silicon, whether in quantum dots or in donor atoms, have long been considered attractive qubits for the implementation of a quantum computer due to the semiconductor vacuum character of silicon and its compatibility…

Mesoscale and Nanoscale Physics · Physics 2015-09-02 M. Urdampilleta , A. Chatterjee , C. C. Lo , T. Kobayashi , J. Mansir , S. Barraud , A. C. Betz , S. Rogge , M. F. Gonzalez-Zalba , J. J. L. Morton

The similarities between gated quantum dots and the transistors in modern microelectronics - in fabrication methods, physical structure, and voltage scales for manipulation - have led to great interest in the development of quantum bits…

In gate-defined semiconductor spin qubits, the highly tunable Heisenberg exchange interaction is leveraged to implement fermionic two-qubit gates such as CZ and SWAP. However, the broader family of fermionic simulation (fSim) gates remains…

We apply the full power of modern electronic band structure engineering and epitaxial heterostructures to design a transistor that can sense and control a single donor electron spin. Spin resonance transistors may form the technological…

We exploit hyperfine interactions in a single Mn-ion confined in a quantum dot (QD) to create a qudit, i.e. a multi-level quantum-bit system, with well defined, addressable and robust set of spin states for the realization of universal…

Mesoscale and Nanoscale Physics · Physics 2019-09-18 Fabrizio Moro , Alistair J. Fielding , Lyudmila Turyanska , Amalia Patanè

We propose an approach to realize quantum gates with electron spins localized in a semiconductor that uses double occupancy to advantage. With a fast (non-adiabatic) time control of the tunnelling, the probability of double occupancy is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 T. A. Kaplan , C. Piermarocchi

Quantum state tomography is a technique in quantum information science used to reconstruct the density matrix of an unknown quantum state, providing complete information about the quantum state. It is of significant importance in fields…

Quantum Physics · Physics 2025-07-23 Wenlong Zhao , Da Zhang , Huili Zhang , Haifeng Yu , Zhang-qi Yin