© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Journal of Physics Conference Series

Optimizing Control of a Hybrid Quantum System of Nitrogen-Vacancy Centers and Superconducting Transmon Qubits

Naseer Muhammad, Muhammad Aziz Majidi

Published Oct 1, 2024• 0 citations

Abstract

Abstract The control of hybrid quantum systems via the application of external fields is rapidly evolving field of research for the development of quantum applications and technologies. We model and optimize the dynamics of a hybrid quantum system consists of two non-local ensembles of nitrogen-vacancy centers and a superconducting transmon qubit mediated by two transmission line resonators. We apply a set of optimized time-dependent external driving field to enhance the system performance to function as a high fidelity state-to-state transfer. The Hamiltonian of the externally driven transmission line resonators is modelled by considering the non-linear transmons. The numerical simulation of the system is done using the optimized parameters of the external fields. By applying the optimized pulses, we have increased the fidelity of the state transfer from 0.7 to 1.0 within 100 ns. By varying the full wave half maxima value (FWHM) of the Gaussian pulse, it result in decreasing the amplitude of the fast oscillating states of the transmon and nitrogen-vacancy ensembles. These optimized external pulses also created a strong coupling between the components of under-consideration physical quantum system, which will eventually increase the fidelity of the system in a relatively faster time.

DOI: 10.1088/1742-6596/2866/1/012080

Related papers

Quantum Dynamics of Two Nitrogen-Vacancy Center Ensembles Coupled to a Driven Superconducting Quantum Circuit

R D Iradat, Muhammad Aziz Majidi, Ressa S. Said

We theoretically model and simulate the dynamics of a hybrid quantum system consisting of two non-local ensembles of nitrogen-vacancy center and a superconducting transmon qubit mediated by two transmission line resonators. We apply a time-dependent external field to enhance this system’s speed and fidelity to function as a controlled-phase gate. Our simulation result shows that a high-fidelity entangled state of two non-local NV spins is 92%. It is achievable under realistic parameter regimes within a timescale of 1.1 nanoseconds. Our result paves the way to improving potential quantum computing and sensing applications.

Journal of Physics Conference Series•Nov 1, 2022•1 citation

Quantum state transfer between nitrogen vacancy center ensembles in hybrid quantum system

Hamad Ali, Abdul Basit, Fazal Badshah +2 more

We propose a system for quantum state transfer (QST) between two nitrogen-vacancy center ensembles (NVEs) coupled to two transmission line resonators (TLRs) via flux qubits (FQs). We study the transfer of an arbitrary quantum state by various system's controlling parameters i.e. , the coupling between nitrogen vacancy ensembles g , the coupling strength between resonators λ for both the resonant and non-resonant interactions in the presence of decoherence. Furthermore, we investigate the dynamics of QST for three different cases, i.e. , g ≫ λ , g ≃ λ and g ≪ λ in detail. It is found that the quantum state can be efficiently transferred between NVEs for suitable values of controlling parameters. We observe that the fidelity of quantum state transfer is about 99 % in all cases for short operational time ( 0.45 μ s ) while in the presence of decoherence fidelity is above 96 % . This reveals that decoherence has no prominent effect on quantum state transfer.

Europhysics Letters (EPL)•Sep 23, 2019•3 citations

Controllable quantum state transfer and entanglement generation between distant nitrogen-vacancy-center ensembles coupled to superconducting flux qubits

Qiong Chen, Wan Li Yang, Mang Feng

We investigate the dissipative dynamics of a hybrid system consisting of two inductively coupled superconducting flux qubits (FQs), each of which couples magnetically with a nitrogen-vacancy-center spin ensemble (NVE). The system displays a series of damped oscillations under various experimental situations, where we obtain analytically the time-dependent populations associated with arbitrary values of the FQ-FQ inductively coupling strength $g$ and the FQ-NVE magnetically coupling strength $G$ in the one-excitation case. Our results show that a reliable high-fidelity quantum state transfer between the two distant NVEs can be realized by modulating the parameters $g$ and $G.$ Furthermore, we also present a potentially practical idea to entangle the two separate NVEs, which is within reach due to the currently available technology.

Physical Review A•Aug 24, 2012•35 citations

Quantum-information processing on nitrogen-vacancy ensembles with the local resonance assisted by circuit QED

Ming‐Jie Tao, Ming Hua, Qing Ai +1 more

With the local resonant interaction between a nitrogen-vacancy-center ensemble (NVE) and a superconducting coplanar resonator, and the single-qubit operation, we propose two protocols for the state transfer between two remote NVEs and for a fast controlled-phase (cphase) gate on these NVEs, respectively. This hybrid quantum system is composed of two distant NVEs coupled to separated high-$Q$ transmission line resonators (TLRs), which are interconnected by a current-biased Josephson-junction superconducting phase qubit. The fidelity of our state-transfer protocol is about $99.63%$ within the operation time of $70.60$ ns. The fidelity of our cphase gate is about $98.15%$ within the operation time of $93.87$ ns. Furthermore, using the cphase gate, we construct a two-dimensional cluster state on NVEs in a $n\ifmmode\times\else\texttimes\fi{}n$ square grid based on the hybrid quantum system for the one-way quantum computation. Our protocol may be more robust, compared with the one based on the superconducting resonators, due to the long coherence time of NVEs at room temperature.

arXiv:1503.02376•Physical Review A•Jun 24, 2015•45 citations

Controlling quantum information processing in hybrid systems on chips

Guy Bensky, Robert Amsüss, Johannes Majer +3 more

We investigate quantum information processing, transfer and storage in hybrid systems comprised of diverse blocks integrated on chips. Strong coupling between superconducting (SC) qubits and ensembles of ultracold atoms or NV-center spins is mediated by a microwave transmission-line resonator that interacts near-resonantly with the atoms or spins. Such hybrid devices allow us to benefit from the advantages of each block and compensate for their disadvantages. Specifically, the SC qubits can rapidly implement quantum logic gates, but are “noisy” (prone to decoherence), while collective states of the atomic or spin ensemble are “quiet”(protected from decoherence) and thus can be employed for storage of quantum information. To improve the overall performance (fidelity) of such devices we discuss dynamical control to optimize quantum state-transfer from a “noisy” qubit to the “quiet” storage ensemble. We propose to maximize the fidelity of transfer and storage in a spectrally inhomogeneous spin ensemble, by pre-selecting the optimal spectral portion of the ensemble. Significant improvements of the overall fidelity of hybrid devices are expected under realistic conditions. Experimental progress towards the realization of these schemes is discussed.

Quantum Information Processing•Oct 3, 2011•22 citations

Coupling a single nitrogen-vacancy center to a superconducting flux qubit in the far-off-resonance regime

Tom Douce, Michael Stern, Nicim Zagury +2 more

We present a theoretical proposal to couple a single nitrogen-vacancy (NV) center to a superconducting flux qubit in the regime where both systems are off resonance. The coupling between both quantum devices is achieved through the strong driving of the flux qubit by a classical microwave field that creates dressed states with an experimentally controlled characteristic frequency. We discuss several applications such as controlling the NV center's state by manipulation of the flux qubit, performing the NV center full tomography and using the NV center as a quantum memory. The effect of decoherence and its consequences to the proposed applications are also analyzed. Our results provide a theoretical framework describing a promising hybrid system for quantum information processing, which combines the advantages of fast manipulation and long coherence times.

arXiv:1507.08099•Physical Review A•Nov 30, 2015•19 citations

Abstract The control of hybrid quantum systems via the application of external fields is rapidly evolving field of research for the development of quantum applications and technologies. We model and optimize the dynamics of a hybrid quantum system consists of two non-local ensembles of nitrogen-vacancy centers and a superconducting transmon qubit mediated by two transmission line resonators. We apply a set of optimized time-dependent external driving field to enhance the system performance to function as a high fidelity state-to-state transfer. The Hamiltonian of the externally driven transmission line resonators is modelled by considering the non-linear transmons. The numerical simulation of the system is done using the optimized parameters of the external fields. By applying the optimized pulses, we have increased the fidelity of the state transfer from 0.7 to 1.0 within 100 ns. By varying the full wave half maxima value (FWHM) of the Gaussian pulse, it result in decreasing the amplitude of the fast oscillating states of the transmon and nitrogen-vacancy ensembles. These optimized external pulses also created a strong coupling between the components of under-consideration physical quantum system, which will eventually increase the fidelity of the system in a relatively faster time.

We theoretically model and simulate the dynamics of a hybrid quantum system consisting of two non-local ensembles of nitrogen-vacancy center and a superconducting transmon qubit mediated by two transmission line resonators. We apply a time-dependent external field to enhance this system’s speed and fidelity to function as a controlled-phase gate. Our simulation result shows that a high-fidelity entangled state of two non-local NV spins is 92%. It is achievable under realistic parameter regimes within a timescale of 1.1 nanoseconds. Our result paves the way to improving potential quantum computing and sensing applications.

We propose a system for quantum state transfer (QST) between two nitrogen-vacancy center ensembles (NVEs) coupled to two transmission line resonators (TLRs) via flux qubits (FQs). We study the transfer of an arbitrary quantum state by various system's controlling parameters i.e. , the coupling between nitrogen vacancy ensembles g , the coupling strength between resonators λ for both the resonant and non-resonant interactions in the presence of decoherence. Furthermore, we investigate the dynamics of QST for three different cases, i.e. , g ≫ λ , g ≃ λ and g ≪ λ in detail. It is found that the quantum state can be efficiently transferred between NVEs for suitable values of controlling parameters. We observe that the fidelity of quantum state transfer is about 99 % in all cases for short operational time ( 0.45 μ s ) while in the presence of decoherence fidelity is above 96 % . This reveals that decoherence has no prominent effect on quantum state transfer.

We investigate the dissipative dynamics of a hybrid system consisting of two inductively coupled superconducting flux qubits (FQs), each of which couples magnetically with a nitrogen-vacancy-center spin ensemble (NVE). The system displays a series of damped oscillations under various experimental situations, where we obtain analytically the time-dependent populations associated with arbitrary values of the FQ-FQ inductively coupling strength

g

and the FQ-NVE magnetically coupling strength

G

in the one-excitation case. Our results show that a reliable high-fidelity quantum state transfer between the two distant NVEs can be realized by modulating the parameters

g

and

G.

Furthermore, we also present a potentially practical idea to entangle the two separate NVEs, which is within reach due to the currently available technology.

With the local resonant interaction between a nitrogen-vacancy-center ensemble (NVE) and a superconducting coplanar resonator, and the single-qubit operation, we propose two protocols for the state transfer between two remote NVEs and for a fast controlled-phase (cphase) gate on these NVEs, respectively. This hybrid quantum system is composed of two distant NVEs coupled to separated high-

Q

transmission line resonators (TLRs), which are interconnected by a current-biased Josephson-junction superconducting phase qubit. The fidelity of our state-transfer protocol is about

99.63%

within the operation time of

70.60

ns. The fidelity of our cphase gate is about

98.15%

within the operation time of

93.87

ns. Furthermore, using the cphase gate, we construct a two-dimensional cluster state on NVEs in a $n\ifmmode\times\else\texttimes\fi{}n$ square grid based on the hybrid quantum system for the one-way quantum computation. Our protocol may be more robust, compared with the one based on the superconducting resonators, due to the long coherence time of NVEs at room temperature.

We investigate quantum information processing, transfer and storage in hybrid systems comprised of diverse blocks integrated on chips. Strong coupling between superconducting (SC) qubits and ensembles of ultracold atoms or NV-center spins is mediated by a microwave transmission-line resonator that interacts near-resonantly with the atoms or spins. Such hybrid devices allow us to benefit from the advantages of each block and compensate for their disadvantages. Specifically, the SC qubits can rapidly implement quantum logic gates, but are “noisy” (prone to decoherence), while collective states of the atomic or spin ensemble are “quiet”(protected from decoherence) and thus can be employed for storage of quantum information. To improve the overall performance (fidelity) of such devices we discuss dynamical control to optimize quantum state-transfer from a “noisy” qubit to the “quiet” storage ensemble. We propose to maximize the fidelity of transfer and storage in a spectrally inhomogeneous spin ensemble, by pre-selecting the optimal spectral portion of the ensemble. Significant improvements of the overall fidelity of hybrid devices are expected under realistic conditions. Experimental progress towards the realization of these schemes is discussed.

We present a theoretical proposal to couple a single nitrogen-vacancy (NV) center to a superconducting flux qubit in the regime where both systems are off resonance. The coupling between both quantum devices is achieved through the strong driving of the flux qubit by a classical microwave field that creates dressed states with an experimentally controlled characteristic frequency. We discuss several applications such as controlling the NV center's state by manipulation of the flux qubit, performing the NV center full tomography and using the NV center as a quantum memory. The effect of decoherence and its consequences to the proposed applications are also analyzed. Our results provide a theoretical framework describing a promising hybrid system for quantum information processing, which combines the advantages of fast manipulation and long coherence times.