Detecting entanglement of two electron spin qubits with witness operators

Abstract

We propose a scheme for detecting entanglement between two electron spin qubits in a double quantum dot using an entanglement witness operator. We first calculate the optimal configuration of the two electron spins, defined as the position in the energy level spectrum where, averaged over the nuclear spin distribution, 1) the probability to have two separated electrons, and 2) the degree of entanglement of the quantum state quantified by the concurrence are both large. Using a density matrix approach, we then calculate the evolution of the expectation value of the witness operator for the two-spin singlet state, taking into account the effect of decoherence due to quantum charge fluctuations modeled as a boson bath. We find that, for large interdot coupling, it is possible to obtain a highly entangled and robust ground state.

4 pages, 3 figures

References in corpus (9)

• Entanglement detection
• Driven coherent oscillations of a single electron spin in a quantum dot
• Coherent control of a single electron spin with electric fields
• Electrically driven single electron spin resonance in a slanting Zeeman field
• Enhancing the Coherence of a Spin Qubit by Operating it as a Feedback Loop That Controls its Nuclear Spin Bath
• Singlet-triplet decoherence due to nuclear spins in a double quantum dot
• Control and coherence of the optical transition of single defect centers in diamond
• Entanglement detection for electrons via witness operators
• Decoherence of Rabi oscillations of electronic spin states in a double quantum dot

Cited by in corpus (5)

• Induced effects of the Dzyaloshinskii-Moriya interaction on the thermal entanglement in spin-1/2 Heisenberg chains
• Quantum correlations in the 1D spin-1/2 Ising model with added Dzyaloshinskii-Moriya interaction
• Robust fermionic-mode entanglement of a nanoelectronic system in non-Markovian environments
• Entanglement generation through particle detection in systems of identical fermions
• Low-noise conditional operation of singlet-triplet coupled quantum dot qubits