Single-electron spins in quantum dots are the leading platform for qubits,while magnons in solids are one of the emerging candidates for quantum technologies.How to manipulate a composite system composed of both syste...Single-electron spins in quantum dots are the leading platform for qubits,while magnons in solids are one of the emerging candidates for quantum technologies.How to manipulate a composite system composed of both systems is an outstanding challenge.Here,we use spin-charge hybridization to effectively couple the single-electron spin state in quantum dots to the cavity and further to the magnons.Through this coupling,quantum dots can entangle and detect magnon states.The detection efficiency can reach 0.94 in a realistic experimental situation.We also demonstrate the electrical tunability of the scheme for various parameters.These results pave a practical pathway for applications of composite systems based on quantum dots and magnons.展开更多
Multi-mode quantum memory is a basic element required for long-distance quantum communication,as well as scalable quantum computation.For on-demand readout and long storage times,control pulses are crucial in order to...Multi-mode quantum memory is a basic element required for long-distance quantum communication,as well as scalable quantum computation.For on-demand readout and long storage times,control pulses are crucial in order to transfer atomic excitations back and forth into spin excitations.Here,we introduce noise-robust composite pulse sequences for high-fidelity excitation transfer in multi-mode quantum memory.These pulses are robust to the deviations in amplitude and the detuning parameters of realistic conditions.We show the efficiency of these composite pulses with a typical rare-earth ion-doped system.This approach could be applied to a variety of quantum memory schemes.展开更多
Single rare-earth ions doped in solids are one kind of the promising candidates for quantum nodes towards a scalable quantum network.Realizing a universal set of high-fidelity gate operations is a central requirement ...Single rare-earth ions doped in solids are one kind of the promising candidates for quantum nodes towards a scalable quantum network.Realizing a universal set of high-fidelity gate operations is a central requirement for functional quantum nodes.Here we propose geometric gate operations using the hybridized states of electron spin and nuclear spin of an ion embedded in a crystal.The fidelities of these geometric gates achieve 0.98 in the realistic experimental situations.We also show the robustness of geometric gates to pulse fluctuations and to environment decoherence.These results provide insights for geometric phases in dissipative systems and show a potential application of high fidelity manipulations for future quantum internet nodes.展开更多
The spin qubit in quantum dots is one of the leading platforms for quantum computation.A crucial requirement for scalable quantum information processing is the high efficient measurement.Here we analyze the measuremen...The spin qubit in quantum dots is one of the leading platforms for quantum computation.A crucial requirement for scalable quantum information processing is the high efficient measurement.Here we analyze the measurement process of a quantum-dot spin qubit coupled to a superconducting transmission line resonator.Especially,the phase shift of the resonator is sensitive to the spin states and the gate operations.The response of the resonator can be used to measure the spin qubit efficiently,which can be extend to read out the multiple spin qubits in a scalable solid-state quantum processor.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11974336)the National Key Research and Development Program of China(Grant No.2017YFA0304100)
文摘Single-electron spins in quantum dots are the leading platform for qubits,while magnons in solids are one of the emerging candidates for quantum technologies.How to manipulate a composite system composed of both systems is an outstanding challenge.Here,we use spin-charge hybridization to effectively couple the single-electron spin state in quantum dots to the cavity and further to the magnons.Through this coupling,quantum dots can entangle and detect magnon states.The detection efficiency can reach 0.94 in a realistic experimental situation.We also demonstrate the electrical tunability of the scheme for various parameters.These results pave a practical pathway for applications of composite systems based on quantum dots and magnons.
基金the National Natural Science Foundation of China(Grant No.11974336)the National Key Research and Development Program of China(Grant No.2017YFA0304100)。
文摘Multi-mode quantum memory is a basic element required for long-distance quantum communication,as well as scalable quantum computation.For on-demand readout and long storage times,control pulses are crucial in order to transfer atomic excitations back and forth into spin excitations.Here,we introduce noise-robust composite pulse sequences for high-fidelity excitation transfer in multi-mode quantum memory.These pulses are robust to the deviations in amplitude and the detuning parameters of realistic conditions.We show the efficiency of these composite pulses with a typical rare-earth ion-doped system.This approach could be applied to a variety of quantum memory schemes.
基金Supported by the National Natural Science Foundation of China(Grant No.11974336)the National Key Research and Development Program of China(Grant No.2017YFA0304100)。
文摘Single rare-earth ions doped in solids are one kind of the promising candidates for quantum nodes towards a scalable quantum network.Realizing a universal set of high-fidelity gate operations is a central requirement for functional quantum nodes.Here we propose geometric gate operations using the hybridized states of electron spin and nuclear spin of an ion embedded in a crystal.The fidelities of these geometric gates achieve 0.98 in the realistic experimental situations.We also show the robustness of geometric gates to pulse fluctuations and to environment decoherence.These results provide insights for geometric phases in dissipative systems and show a potential application of high fidelity manipulations for future quantum internet nodes.
基金the National Basic Research Programme of China(No.2017YFA0304100)the National Natural Science Foundation of China(No.11974336).
文摘The spin qubit in quantum dots is one of the leading platforms for quantum computation.A crucial requirement for scalable quantum information processing is the high efficient measurement.Here we analyze the measurement process of a quantum-dot spin qubit coupled to a superconducting transmission line resonator.Especially,the phase shift of the resonator is sensitive to the spin states and the gate operations.The response of the resonator can be used to measure the spin qubit efficiently,which can be extend to read out the multiple spin qubits in a scalable solid-state quantum processor.
