Abstract The subwavelength array of quantum emitters provides an ideal platform for exploring rich many-body dynamics, such as super- and subradiance. In this paper, we explore the dynamics of spin wave exchange between two dipole-coupled atomic ring arrays. Subradiant spin waves lead to low-loss and high efficiency of ring-to-ring transfer. The optimal subradiant spin wave exchange occurs at appropriate separations between coplanar rings, despite the fact that the energy transfer efficiency is monotonically enhanced (in the regime ⩽ λ 0 / 2 ) as the rings’ separation decreases. However, the spin wave will scatter due to the dephasing mechanism of close-by atom pairs, as the separation of two rings is too small. With the increase in the number of atoms on the ring, the subradiant shielding effect also strengthens, leading to a shorter distance for the transfer of spin waves. We investigate the rotation of one of the rings and find that the optimal spin wave exchange corresponds to the scenario where the line connecting the two nearest atoms of the two rings aligns with the center of the circle. Moreover, we study the influence of transition dipole moment orientations on the effective interaction between two atomic rings. We observe that there is a critical point where the effective interaction strength changes dramatically owing to the cooperative effect of the subwavelength atomic array. We believe that our results could be important for quantum information processing based on atomic arrays.Abstract The subwavelength array of quantum emitters provides an ideal platform for exploring rich many-body dynamics, such as super- and subradiance. In this paper, we explore the dynamics of spin wave exchange between two dipole-coupled atomic ring arrays. Subradiant spin waves lead to low-loss and high efficiency of ring-to-ring transfer. The optimal subradiant spin wave exchange occurs at appropriate separations between coplanar rings, despite the fact that the energy transfer efficiency is monotonically enhanced (in the regime ⩽ λ 0 / 2 ) as the rings’ separation decreases. However, the spin wave will scatter due to the dephasing mechanism of close-by atom pairs, as the separation of two rings is too small. With the increase in the number of atoms on the ring, the subradiant shielding effect also strengthens, leading to a shorter distance for the transfer of spin waves. We investigate the rotation of one of the rings and find that the optimal spin wave exchange corresponds to the scenario where the line connecting the two nearest atoms of the two rings aligns with the center of the circle. Moreover, we study the influence of transition dipole moment orientations on the effective interaction between two atomic rings. We observe that there is a critical point where the effective interaction strength changes dramatically owing to the cooperative effect of the subwavelength atomic array. We believe that our results could be important for quantum information processing based on atomic arrays.

New Journal of PhysicsSep 26, 20233 citations

Spin effects in the quantum many-particles systems

Mariya Iv. Trukhanova, L. S. Kuz’menkov

arXiv:1403.2981Mar 12, 20140 citations

Quantum communication through a spin ring with twisted boundary conditions

Sougato Bose, Bai-Qi Jin, V. E. Korepin

We investigate quantum communication between the sites of a spin ring with twisted boundary conditions. Such boundary conditions can be achieved by a magnetic flux through the ring. We find that a nonzero twist can improve communication through finite odd-numbered rings and enable high-fidelity multiparty quantum communication through spin rings (working near perfectly for rings of five and seven spins). We show that in certain cases, the twist results in the complete blockage of quantum-information flow to a certain site of the ring. This effect can be exploited to interface and entangle a flux qubit and a spin qubit without embedding the latter in a magnetic field.We investigate quantum communication between the sites of a spin ring with twisted boundary conditions. Such boundary conditions can be achieved by a magnetic flux through the ring. We find that a nonzero twist can improve communication through finite odd-numbered rings and enable high-fidelity multiparty quantum communication through spin rings (working near perfectly for rings of five and seven spins). We show that in certain cases, the twist results in the complete blockage of quantum-information flow to a certain site of the ring. This effect can be exploited to interface and entangle a flux qubit and a spin qubit without embedding the latter in a magnetic field.

arXiv:quant-ph/0409134Physical Review AAug 30, 200530 citations

Kondo effect in a many-electron quantum ring

K. Ensslin

Bulletin of the American Physical SocietyMar 25, 20050 citations

Tailoring effective exchange interactions via domain walls in coupled Heisenberg rings

Vanita Srinivasa, Jeremy Levy

The nature of the exchange coupling variation in an antiferromagnetic spin- $\frac{1}{2}$ system can be used to tailor its ground-state properties. In particular, dimerized Heisenberg rings containing domain walls have localized states that can serve as ``flying spin qubits'' when the domain walls are moved. We show theoretically that when two of these rings are coupled, the movement of the domain walls leads to modulation of the effective exchange interaction between the qubits. Appropriately chosen configurations of domain walls can give rise to ferromagnetic effective exchange. We describe how these spin rings may be used as basic building blocks to construct quantum spin systems whose properties are tunable by virtue of the exchange variation within the rings.The nature of the exchange coupling variation in an antiferromagnetic spin-$\frac{1}{2}$ system can be used to tailor its ground-state properties. In particular, dimerized Heisenberg rings containing domain walls have localized states that can serve as ``flying spin qubits'' when the domain walls are moved. We show theoretically that when two of these rings are coupled, the movement of the domain walls leads to modulation of the effective exchange interaction between the qubits. Appropriately chosen configurations of domain walls can give rise to ferromagnetic effective exchange. We describe how these spin rings may be used as basic building blocks to construct quantum spin systems whose properties are tunable by virtue of the exchange variation within the rings.

arXiv:0904.2783Physical Review BJul 14, 20097 citations

The nature of the exchange coupling variation in an antiferromagnetic spin-

\frac{1}{2}

system can be used to tailor its ground-state properties. In particular, dimerized Heisenberg rings containing domain walls have localized states that can serve as ``flying spin qubits'' when the domain walls are moved. We show theoretically that when two of these rings are coupled, the movement of the domain walls leads to modulation of the effective exchange interaction between the qubits. Appropriately chosen configurations of domain walls can give rise to ferromagnetic effective exchange. We describe how these spin rings may be used as basic building blocks to construct quantum spin systems whose properties are tunable by virtue of the exchange variation within the rings.