Capacitative coupling of singlet-triplet qubits in different inter-qubit geometries

Abstract

In the singlet-triplet qubit architecture, the two-qubit interactions required in universal quantum computing can be implemented by capacitative coupling, by exploiting the charge distribution differences of the singlet and triplet states. The efficiency of this scheme is limited by decoherence, that can be mitigated by stronger coupling between the qubits. In this paper, we study the capacitative coupling of singlet-triplet qubits in different geometries of the two-qubit system. The effects of the qubit-qubit distance and the relative orientation of the qubits on the capacitative coupling strength are discussed using an accurate microscopic model and exact diagonalization of it. We find that the trapezoidal quantum dot formations allow strong coupling with low charge distribution differences between the singlet and triplet states. The analysis of geometry on the capacitative coupling is also extended to the many-qubit case and the creation of cluster states.

References in corpus (6)

• Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits
• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
• Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit
• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Conditional operation of a spin qubit
• Quantum gates between capacitively coupled double quantum dot two-spin qubits

Cited by in corpus (3)

• Validity of the single-particle description and charge noise resilience for multielectron quantum dots
• Extended orbital modeling of spin qubits in double quantum dots
• A robust operating point for capacitively coupled singlet-triplet qubits