| Full text | |
| Author(s): |
Castelano, Leonardo K.
;
de Lima, Emanuel F.
;
Madureira, Justino R.
;
Degani, Marcos H.
;
Maialle, Marcelo Z.
Total Authors: 5
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW B; v. 97, n. 23, p. 12-pg., 2018-06-04. |
| Abstract | |
We theoretically investigate electron spin operations driven by applied electric fields in a semiconductor double quantum dot (DQD) formed in a nanowire with longitudinal potential modulated by local gating. We develop a model that describes the process of loading and unloading the DQD taking into account the overlap between the electron wave function and the leads. Such a model considers the spatial occupation and the spin Pauli blockade in a time-dependent fashion due to the highly mixed states driven by the external electric field. Moreover, we present a road map based on the quantum optimal control theory (QOCT) to find a specific electric field that performs two-qubit quantum gates on a faster timescale and with higher possible fidelity. By employing the QOCT, we demonstrate the possibility of performing within high efficiency a universal set of quantum gates {CNOT, H, and T}, where CNOT is the controlled-NOT gate, H is the Hadamard gate, and T is the pi/8 gate, even in the presence of the loading/unloading process and charge noise effects. Furthermore, by varying the intensity of the applied magnetic field B, the optimized fidelity of the gates oscillates with a period inversely proportional to the gate operation time t(f) . This behavior can be useful to attain higher fidelity for fast gate operations (>1 GHz) by appropriately choosing B and t(f) to produce a maximum of the oscillation. (AU) | |
| FAPESP's process: | 12/13052-6 - Transport properties and quantum computation in nanostructures |
| Grantee: | Leonardo Kleber Castelano |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 17/10190-2 - Spin dynamics and qubit operations on semiconductor nanostructures |
| Grantee: | Marcelo Zoéga Maialle |
| Support Opportunities: | Regular Research Grants |