Abstract The optical absorption spectrum of the hybrid system composed of the nitrogen-vacancy (NV) center coupled to the mechanical resonators is. investigated. Based on the pump-probe technology, the electronically induced transparency (EIT) is observed and the reasonable explanation for this transparency is given. We demonstrate that the position of the transparency is equal to the detuning difference. In addition, a completely new scheme to measure the coupling between the NV center and current carrying carbon nanotube mechanical resonator is obtained. Furthermore, an optical approach to measure the frequency of the vibrating graphene mechanical resonator is proposed. This work can provide some help for the application in the field of high-precision measurement and quantum information processing.
Abstract The optical absorption spectrum of the hybrid system composed of the nitrogen-vacancy (NV) center coupled to the mechanical resonators is. investigated. Based on the pump-probe technology, the electronically induced transparency (EIT) is observed and the reasonable explanation for this transparency is given. We demonstrate that the position of the transparency is equal to the detuning difference. In addition, a completely new scheme to measure the coupling between the NV center and current carrying carbon nanotube mechanical resonator is obtained. Furthermore, an optical approach to measure the frequency of the vibrating graphene mechanical resonator is proposed. This work can provide some help for the application in the field of high-precision measurement and quantum information processing.
In this paper, we theoretically investigate the optical absorption spectrum of the nanodiamond system consisting of the nitrogen- vacancy (NV) spin coupled to the mechanical resonator. We show how the widths of electromagnetically induced transparency (EIT) phenomenon windows are manipulated by varying the system parameters. The better transparency phenomenon effect can be achieved by appropriately reducing the decay rates of the mechanical resonator. It is shown that the probe absorption spectrum exhibits an asymmetric property. In particular, the coupling strength between the NV spin and the mechanical oscillation of the nanodiamond can be detected, which is realized by measuring the width of two peaks in the pump-probe spectrum. The study may provide a potential application in the fields of high precision measurement and quantum information processing.
With the great improvement of nanotechnology, it is now possible to fabricate mechanical resonator with dimension on a micro and even nanometer scale.Because of its high vibration frequency, quality factor, very small mass, and low intrinsic dissipation, nanomechanical resonator has important applications in the field of high-precision displacement detection, force detection, mass measurement, and accurate quantum computation.Mechanical resonator is also a promising candidate for observing quantum effects in macroscopic objects.By coupling nanomechanical resonator to other solid-state system such as optical cavity, microwave cavity, nitrogen-vacancy center (NV center) and superconducting qubits, researchers have successfully cooled the mechanical resonator to its quantum ground state, which paves the way for observing nonclassical states in resonator such as superposition state and Fock state.On the other hand, the nitrogenvacancy center in diamond has attracted more and more attention because of its advantages of long coherence time at room temperature, the ability to implement initialization and readout, and microwave control.Moreover, these NV centers can be used to detect weak magnetic field and electric field at room temperature.By using both laser field and microwave field, one can implement the manipulation, storage, and readout of the quantum information.In addition, because NV centers couple to both optical field and microwave field, they can also be used as a quantum interface between optical system and solid-state system.This provides a promising platform to study novel quantum phenomena based on NV centers separated by long distances.The nitrogen-vacancy center in diamond coupled to nanomechanical resonator can be used in precision measurement and quantum information processing, which has become a hot research topic.In this paper, we study the dynamics of quadrature squeezing of the phonon field in the system consisting of nitrogen-vacancy centers in diamond coupled to both cavity field and mechanical resonator.The effects of initial state of nitrogen-vacancy center and the coupling strength between nitrogen-vacancy center and mechanical resonator on the quadrature squeezing of the phonon field are analyzed.It is shown that the phonon field squeezed state with longtime and high-degree can be generated.The physical reason is that the mechanical resonator has the largest coherence.Moreover, the non-classical property of quadrature squeezing of mechanical resonator can be achieved by manipulating the initial state of nitrogen-vacancy center and magnetic field gradient.The proposal may provide a theoretical way to control and manipulate the quadrature squeezing of the phonon field.The results obtained here may have great significance and applications in the field of quantum information processing and precision measurement.
We theoretically propose a multiple-mode-coupling hybrid quantum system comprising two-mode-coupling nanomechanical carbon nanotube (CNT) resonators realized by a phase-dependent phonon-exchange interaction interacting with the same nitrogen-vacancy (NV) center in diamond. We investigate the coherent optical responses of the NV center under the condition of resonance and detuning. In particular, two-color electromagnetically induced transparency (EIT) can be achieved by controlling the system parameters and coupling regimes. Combining the spin-phonon interactions and phonon-phonon coupling with the modulation phase, the switching of one and two EIT windows has been demonstrated, which generates a light delay or advance. The slow-to-fast and fast-to-slow light transitions have been studied in different coupling regimes, and the switch between slow and fast light can be controlled periodically by tuning the modulation phase. The study can be applied to phonon-mediated optical information storage or information processing with spin qubits based on multiple-mode hybrid quantum systems.
In a diamond, the mechanical vibration-induced strain can lead to interaction between the mechanical mode and the nitrogen-vacancy (NV) centers. In this work, we propose to utilize the strain-induced coupling for the quantum non-demolition (QND) single phonon measurement and memory in a diamond. The single phonon in a diamond mechanical resonator can be perfectly absorbed and emitted by the NV centers ensemble (NVE) with adiabatically tuning the microwave driving. An optical laser drives the NVE to the excited states, which have much larger coupling strength to the mechanical mode. By adiabatically eliminating the excited states under large detuning limit, the effective coupling between the mechanical mode and the NVE can be used for QND measurement of the single phonon state. Under realistic experimental conditions, we numerically simulate the scheme. It is found that the fidelity of the absorbing and emitting process can reach a much high value. The overlap between the input and the output phonon shapes can reach 98.57%.
Negatively charged nitrogen-vacancy (NV${}^{\ensuremath{-}}$) color centers in diamond have generated much interest for use in quantum technology. Despite the progress made in developing their applications, many questions about the basic properties of NV${}^{\ensuremath{-}}$ centers remain unresolved. Understanding these properties can validate theoretical models of NV${}^{\ensuremath{-}}$, improve their use in applications, and support their development into competitive quantum devices. In particular, knowledge of the phonon modes of the 1A1 electronic state is key for understanding the optical pumping process. Using pump-probe spectroscopy, we measured the phonon sideband of the ${}^{1}E\ensuremath{\rightarrow}{}^{1}{A}_{1}$ electronic transition in the NV${}^{\ensuremath{-}}$ center. From this we calculated the ${}^{1}E\ensuremath{\rightarrow}{}^{1}{A}_{1}$ one-phonon absorption spectrum and found it to differ from that of the ${}^{3}E\ensuremath{\rightarrow}{}^{3}{A}_{2}$ transition, a result which is not anticipated by previous group-theoretical models of the NV${}^{\ensuremath{-}}$ electronic states. We identified a high-energy 169-meV localized phonon mode of the 1A1 level.
Abstract Hybrid quantum devices, in which disparate quantum elements are combined in order to achieve enhanced functionality, have received much attention in recent years due to their exciting potential to address key problems in quantum information processing, communication, and control. Specifically, significant progress has been made in the field of hybrid mechanical devices, in which a qubit is coupled to a mechanical oscillator. High cooperativity in such devices has been demonstrated with superconducting qubits, and coupling defect qubits to mechanical elements via crystal strain has enabled novel methods of qubit measurement and control. In this paper we demonstrate the fabrication of diamond optomechanical crystals (OMCs) with embedded nitrogen-vacancy (NV) centers, a preliminary step toward reaching the quantum regime with defect qubit hybrid mechanical devices. We measure optical and mechanical resonances of diamond OMCs as well as the spin coherence of single embedded NV centers. We find that the spin has long coherence times T 2 * = 1.5 μ s and T 2 = 72 μ s despite its proximity to nanofabricated surfaces. Finally, we discuss potential improvements of these devices and prospects for future experiments in the quantum regime.