Limits...
Generation of macroscopic Schr ö dinger cat state in diamond mechanical resonator

View Article: PubMed Central - PubMed

ABSTRACT

We propose a scheme to generate macroscopic Schrödinger cat state (SCS) in diamond mechanical resonator (DMR) via the dynamical strain-mediated coupling mechanism. In our model, the direct coupling between the nitrogen-vacancy (NV) center and lattice strain field enables coherent spin–phonon interactions in the quantum regime. Based on a cyclic Δ-type transition structure of the NV center constructed by combining the quantized mechanical strain field and a pair of external microwave fields, the populations of the different energy levels can be selectively transferred by controlling microwave fields, and the SCS can be created by adjusting the controllable parameters of the system. Furthermore, we demonstrate the nonclassicality of the mechanical SCS both in non-dissipative case and dissipative case. The experimental feasibility and challenge are justified using currently available technology.

No MeSH data available.


(a–g) Represent the Wigner function ( with the displacement operator  (αW = x + iy is the arbitrary complex number), the density operator ρ of the mechanical phonon state and the parity operator P = exp(iπa†a)) of SCS at the different times t = 0, 9, 17, 28, 39, 47, 56. The upper and lower panel represent the non-dissipative case (κ = 0) and dissipative case (κ = 0.02), respectively. The other parameters are the same as the Fig. 2(a).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120327&req=5

f4: (a–g) Represent the Wigner function ( with the displacement operator (αW = x + iy is the arbitrary complex number), the density operator ρ of the mechanical phonon state and the parity operator P = exp(iπa†a)) of SCS at the different times t = 0, 9, 17, 28, 39, 47, 56. The upper and lower panel represent the non-dissipative case (κ = 0) and dissipative case (κ = 0.02), respectively. The other parameters are the same as the Fig. 2(a).

Mentions: To show the interference fringes and nonclassicality of the mechanical SCS, the phase-space quasiprobability distribution using the Wigner function was also calculated in the phase space51, as shown in Fig. 4. In general, the quantum state could be judged to be nonclassical by checking that the Wigner function is negative in phase space. The Wigner function has the relation with the density operator ρ of the quantum state in the Fock state representation as with the displacement operator (αW = x + iy is the arbitrary complex number) and the parity operator P = exp(iπa†a)52. In Fock space, we have P/n〉 = (−1)n /n〉. Similar to the Husimi Q function, we plot the Wigner function on the SCS at the different times under the non-dissipative case (upper panel of the Fig. 4) and dissipative case (lower panel of the Fig. 4). One can find that the interference fringes appear under these two different cases, and it verifies the quantum features of the mechanical SCS of DMR due to the negative values of the Wigner function. Note that several experimental schemes5354 have been proposed to measure the Winger function with respect to the vibrational cat state.


Generation of macroscopic Schr ö dinger cat state in diamond mechanical resonator
(a–g) Represent the Wigner function ( with the displacement operator  (αW = x + iy is the arbitrary complex number), the density operator ρ of the mechanical phonon state and the parity operator P = exp(iπa†a)) of SCS at the different times t = 0, 9, 17, 28, 39, 47, 56. The upper and lower panel represent the non-dissipative case (κ = 0) and dissipative case (κ = 0.02), respectively. The other parameters are the same as the Fig. 2(a).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120327&req=5

f4: (a–g) Represent the Wigner function ( with the displacement operator (αW = x + iy is the arbitrary complex number), the density operator ρ of the mechanical phonon state and the parity operator P = exp(iπa†a)) of SCS at the different times t = 0, 9, 17, 28, 39, 47, 56. The upper and lower panel represent the non-dissipative case (κ = 0) and dissipative case (κ = 0.02), respectively. The other parameters are the same as the Fig. 2(a).
Mentions: To show the interference fringes and nonclassicality of the mechanical SCS, the phase-space quasiprobability distribution using the Wigner function was also calculated in the phase space51, as shown in Fig. 4. In general, the quantum state could be judged to be nonclassical by checking that the Wigner function is negative in phase space. The Wigner function has the relation with the density operator ρ of the quantum state in the Fock state representation as with the displacement operator (αW = x + iy is the arbitrary complex number) and the parity operator P = exp(iπa†a)52. In Fock space, we have P/n〉 = (−1)n /n〉. Similar to the Husimi Q function, we plot the Wigner function on the SCS at the different times under the non-dissipative case (upper panel of the Fig. 4) and dissipative case (lower panel of the Fig. 4). One can find that the interference fringes appear under these two different cases, and it verifies the quantum features of the mechanical SCS of DMR due to the negative values of the Wigner function. Note that several experimental schemes5354 have been proposed to measure the Winger function with respect to the vibrational cat state.

View Article: PubMed Central - PubMed

ABSTRACT

We propose a scheme to generate macroscopic Schrödinger cat state (SCS) in diamond mechanical resonator (DMR) via the dynamical strain-mediated coupling mechanism. In our model, the direct coupling between the nitrogen-vacancy (NV) center and lattice strain field enables coherent spin–phonon interactions in the quantum regime. Based on a cyclic Δ-type transition structure of the NV center constructed by combining the quantized mechanical strain field and a pair of external microwave fields, the populations of the different energy levels can be selectively transferred by controlling microwave fields, and the SCS can be created by adjusting the controllable parameters of the system. Furthermore, we demonstrate the nonclassicality of the mechanical SCS both in non-dissipative case and dissipative case. The experimental feasibility and challenge are justified using currently available technology.

No MeSH data available.