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 (26)

• Quantum entanglement
• Quantum Computation with Quantum Dots
• Elementary gates for quantum computation
• Three qubits can be entangled in two inequivalent ways
• Distributed Entanglement
• Persistent entanglement in arrays of interacting particles
• Measurement-based quantum computation with cluster states
• Electron spin relaxation by nuclei in semiconductor quantum dots
• Electron spin decoherence in quantum dots due to interaction with nuclei
• Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits
• Control and Detection of Singlet-Triplet Mixing in a Random Nuclear Field
• Triplet-Singlet Spin Relaxation via Nuclei in a Double Quantum Dot
• Universal quantum control of two-electron spin quantum bits using dynamic nuclear polarization
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• Electrometry Using Coherent Exchange Oscillations in a Singlet-Triplet-Qubit
• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Charge fluctuation induced dephasing of exchange coupled spin qubits
• Conditional operation of a spin qubit
• Cluster States From Heisenberg Interaction
• Quantum gates between capacitively coupled double quantum dot two-spin qubits
• Implications of Simultaneous Requirements for Low Noise Exchange Gates in Double Quantum Dots
• Decoherence of spin qubits due to a nearby charge fluctuator in gate-defined double dots
• Electrically controlled quantum gates for two-spin qubits in two double quantum dots
• Configuration interaction calculations of the controlled phase gate in double quantum dot qubits
• Maximal tripartite entanglement between singlet-triplet qubits in quantum dots
• Non-adiabatic charge state transitions in singlet-triplet qubits

Cited by in corpus (7)

• Validity of the single-particle description and charge noise resilience for multielectron quantum dots
• Extended orbital modeling of spin qubits in double quantum dots
• Probing two-qubit capacitive interactions beyond bilinear regime using dual Hamiltonian parameter estimations
• Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field
• Simulation of Coupling Strength of Capacitively Coupled Singlet-Triplet Qubits
• Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
• A robust operating point for capacitively coupled singlet-triplet qubits