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Related papers: Charge qubit rotations in a double-dot nanostructu…

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We propose a scheme to prepare arbitrary superpositions of quantum states in double quantum--dots irradiated by coherent microwave pulses. Solving the equations of motion for the dot density matrix, we find that dephasing rates for such…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 T. Brandes , F. Renzoni , R. H. Blick

We consider an electron confined in a gated nanowire quantum dot (NQD) with arbitrarily strong spin-orbit coupling (SOC) and weak static magnetic field, and treat the latter as a perturbation to seek the maximal spin-motion entangled states…

Mesoscale and Nanoscale Physics · Physics 2024-04-23 Kuo Hai , Xuefang Deng , Qiong Chen , Wenhua Hai

We study analytically and numerically the problem of two qubits with fixed coupling irradiated with quantum or classical fields. In the classical case, we derive an effective Hamiltonian, and construct composite pulse sequences leading to a…

Superconductivity · Physics 2008-12-15 Jian Li , K. Chalapat , G. S. Paraoanu

Since the first demonstration of coherent control of a quantum state of a superconducting charge qubit a variety of Josephson-junction-based qubits have been implemented with remarkable progress in coherence time and read-out schemes.…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 T. Yamamoto , Yu. A. Pashkin , O. Astafiev , Y. Nakamura , J. S. Tsai

We analyze the operation of quantum gates for neutral atoms with qubits that are delocalized in space, i.e., the computational basis states are defined by the presence of a neutral atom in the ground state of one out of two trapping…

Quantum Physics · Physics 2009-11-07 J. Mompart , K. Eckert , W. Ertmer , G. Birkl , M. Lewenstein

Universal quantum computation requires high fidelity single qubit rotations and controlled two qubit gates. Along with high fidelity single qubit gates, strong efforts have been made in developing robust two qubit logic gates in…

Mesoscale and Nanoscale Physics · Physics 2016-10-20 D. R. Ward , Dohun Kim , D. E. Savage , M. G. Lagally , R. H. Foote , Mark Friesen , S. N. Coppersmith , Mark A. Eriksson

We discuss the implementation of quantum gate operations in a self-assembled dipolar crystal of polar molecules. Here qubits are encoded in long-lived spin states of the molecular ground state and stabilized against collisions by repulsive…

Quantum Physics · Physics 2011-07-15 M. Ortner , Y. L. Zhou , P. Rabl , P. Zoller

We theoretically investigate the formation of $W$ states in a tripartite system composed of three charge qubits coupled to vibrational modes. The electromechanical coupling is responsable for second order virtual processes that result in an…

Quantum Physics · Physics 2021-04-14 H. G. Mendonça , F. M. Souza

The localization of two interacting electrons in a coupled-quantum-dots semiconductor structure is demonstrated through numerical calculations of the time evolution of the two-electron wave function including the Coulomb interaction between…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 P. I. Tamborenea , H. Metiu

We considered a nanoelectromechanical system consisting of a movable Cooper-pair box qubit which is subject to an electrostatic field, and coupled to the two bulk superconductors via tunneling processes. We suggest that qubit dynamics is…

Mesoscale and Nanoscale Physics · Physics 2021-12-02 O. M. Bahrova , L Y. Gorelik , S. I. Kulinich

Taking the excess electron spin in a unit cell of semiconductor multiple quantum-dot structure as a qubit, we can implement scalable quantum computation without resorting to spin-spin interactions. The technique of single electron…

Quantum Physics · Physics 2007-05-23 Wei-Min Zhang , Yin-Zhong Wu , Chopin Soo

A fundamental goal in the manipulation of quantum systems is the achievement of many coherent oscillations within the characteristic dephasing time T2*[1]. Most manipulations of electron spins in quantum dots have focused on the…

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…

We investigate charge dynamics in a two-electron double quantum dot. The quantum dot is manipulated by using a time-dependent external voltage that induces charge oscillations between the dots. We study the dependence of the charge dynamics…

Mesoscale and Nanoscale Physics · Physics 2010-12-23 Jani Särkkä , Ari Harju

We present a proposal for deterministic quantum teleportation of electrons in a semiconductor nanostructure consisting of a single and a double quantum dot. The central issue addressed in this paper is how to design and implement the most…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 R. L. de Visser , M. Blaauboer

The behavior of simply pulsed qubits (quantum systems with two linearly independent states) may be characterized by the energy difference $\Delta E$ between the two states of the qubit and by an external stimulating potential $V(t)$ that…

Quantum Physics · Physics 2007-05-23 A. Chalastaras , L. Kaplan , Kh. Kh. Shakov , M. Smith , J. H. McGuire

We present a theoretical analysis of the capacitance of a double quantum dot in the charge and spin qubit configurations probed at high-frequencies. We find that in general the total capacitance of the system consists of two state-dependent…

Mesoscale and Nanoscale Physics · Physics 2017-01-25 R. Mizuta , R. M. Otxoa , A. C. Betz , M. F. Gonzalez-Zalba

We study the dynamics of a charge qubit that is capacitively coupled to an open double quantum dot. Depending on the qubit state, the transport through the open quantum dot may be resonant or off-resonant, such that the qubit affects the…

Mesoscale and Nanoscale Physics · Physics 2010-03-09 C. Kreisbeck , F. J. Kaiser , S. Kohler

One fundamental requirement for quantum computation is to perform universal manipulations of quantum bits at rates much faster than the qubit's rate of decoherence. Recently, fast gate operations have been demonstrated in logical spin…

Mesoscale and Nanoscale Physics · Physics 2010-09-28 Sandra Foletti , Hendrik Bluhm , Diana Mahalu , Vladimir Umansky , Amir Yacoby

Semiconductor quantum dots are an attractive platform for the realisation of quantum processors. To achieve long-range coupling between them, quantum dots have been integrated into microwave cavities. However, it has been shown that their…