Improving intrinsic decoherence in multiple-quantum-dot charge qubits
Journal Article
We discuss decoherence in charge qubits formed by multiple lateral quantum dots in the framework of the spin-boson model and the Born-Markov approximation. We consider the intrinsic decoherence caused by the coupling to bulk phonon modes. Two distinct quantum dot configurations are studied: (i) Three quantum dots in a ring geometry with one excess electron in total and (ii) arrays of quantum dots where the computational basis states form multipole charge configurations. For the three-dot qubit, we demonstrate the possibility of performing one- and two-qubit operations by solely tuning gate voltages. Compared to a previous proposal involving a linear three-dot spin qubit, the three-dot charge qubit allows for less overhead on two-qubit operations. For small interdot tunnel amplitudes, the three-dot qubits have Q factors much higher than those obtained for double-dot systems. The high-multipole dot configurations also show a substantial decrease in decoherence at low operation frequencies when compared to the double-dot qubit. © 2007 The American Physical Society.
Full Text
Duke Authors
Cited Authors
- Hentschel, M; Valente, DCB; Mucciolo, ER; Baranger, HU
Published Date
- December 12, 2007
Published In
Volume / Issue
- 76 / 23
Electronic International Standard Serial Number (EISSN)
- 1550-235X
International Standard Serial Number (ISSN)
- 1098-0121
Digital Object Identifier (DOI)
- 10.1103/PhysRevB.76.235309
Citation Source
- Scopus