Charge-Qubit Operation of an Isolated Double Quantum Dot

Abstract

We have investigated coherent time evolution of pseudomolecular states of an isolated (leadless) silicon double quantum dot, where operations are carried out via capacitively coupled elements. Manipulation is performed by short pulses applied to a nearby gate, and measurement is performed by a single-electron transistor. The electrical isolation of this qubit results in a significantly longer coherence time than previous reports for semiconductor charge qubits realized in artificial molecules.

Control of electrostatic coupling observed for Si double quantum dot structures

“…A coherent two level system formed in DQDs has been studied for realizing qubits for the quantum computer [1]. It is vital to control the coupling between DQDs for tuning the two level systems.…”

Study of Single-Charge Polarization on two Charge Qubits Integrated onto a Double Single-Electron Transistor Readout

“…Double Quantum Dots (DQDs) have been extensively studied as a candidate for the charge qubit. Early DQD research has been done for GaAs/AlGaAs hetero-structures [1], but silicon based DQDs have recently been fabricated using the top-down fabrication technique, and a long decoherence time has been demonstrated [2]. Silicon based DQDs are also preferred because of their compatibility with the existing silicon fabrication process.…”

Controlled high-fidelity navigation in the charge stability diagram of a double quantum dot

“…Since the seminal Letter of Grossmann et al [8] a number of theoretical and experimental works have addressed the issue of controlling the localization of an electron state in a double well potential [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. These various control strategies include the use of analytically wellestablished phenomena like the paradigmatic LandauZener (LZ) transition [12][13][14], Landau-Zener-Stückelberg interferometry [15,16], the composite pulse (CP) protocol and several other two-level control strategies [12,[24][25][26][27], and OCT [18][19][20][21][22][23].…”