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Hybrid Toffoli gate on photons and quantum spins.

Luo MX, Ma SY, Chen XB, Wang X - Sci Rep (2015)

Bottom Line: We present implementations of a key quantum circuit: the three-qubit Toffoli gate.The three general controlled-NOT gates are involved using an auxiliary photon with two degrees of freedom.Our results show that photons and quantum spins may be used alternatively in quantum information processing.

View Article: PubMed Central - PubMed

Affiliation: Information Security and National Computing Grid Laboratory, Southwest Jiaotong University, Chengdu 610031, China.

ABSTRACT
Quantum computation offers potential advantages in solving a number of interesting and difficult problems. Several controlled logic gates, the elemental building blocks of quantum computer, have been realized with various physical systems. A general technique was recently proposed that significantly reduces the realization complexity of multiple-control logic gates by harnessing multi-level information carriers. We present implementations of a key quantum circuit: the three-qubit Toffoli gate. By exploring the optical selection rules of one-sided optical microcavities, a Toffoli gate may be realized on all combinations of photon and quantum spins in the QD-cavity. The three general controlled-NOT gates are involved using an auxiliary photon with two degrees of freedom. Our results show that photons and quantum spins may be used alternatively in quantum information processing.

No MeSH data available.


Related in: MedlinePlus

Reflection coefficients versus the cavity leakage ratio κs/κ and the cooperativity C under resonant conditions.(a) Reflectance /r/ and (b) reflectance /r0/ under resonant conditions.
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f5: Reflection coefficients versus the cavity leakage ratio κs/κ and the cooperativity C under resonant conditions.(a) Reflectance /r/ and (b) reflectance /r0/ under resonant conditions.

Mentions: These complex coefficients indicate that the reflected light may experience a phase shift3233343536444546. Under resonant conditions Δωc = Δωx = 0, the reflection coefficients /r/ and /r0/ are evaluated in Fig. 5, and the phase shifts θ and θ0 are evaluated in Fig. 6 inrelation to the decay ratios of cavity κs/κ and the cooperativity parameter C = g2/(κγ) of cavity QED5657, which is a geometric parameter that characterizes the absorptive, emissive, or dispersive coupling of an atom to the cavity mode. Based on Fig. 5, the reflection coefficients will satisfy /r/ ≈ 1 and /r0/ ≈ 1 when C ≫ 10 and κs/κ → 0, and these additional conditions are not required for relative phase shifts θ0 = π and θ = π because r and r0 are real under the resonant conditions Δωc = Δωx = 0. Hence, the real reflection coefficients r and r0 will be considered under the resonant conditions.


Hybrid Toffoli gate on photons and quantum spins.

Luo MX, Ma SY, Chen XB, Wang X - Sci Rep (2015)

Reflection coefficients versus the cavity leakage ratio κs/κ and the cooperativity C under resonant conditions.(a) Reflectance /r/ and (b) reflectance /r0/ under resonant conditions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644947&req=5

f5: Reflection coefficients versus the cavity leakage ratio κs/κ and the cooperativity C under resonant conditions.(a) Reflectance /r/ and (b) reflectance /r0/ under resonant conditions.
Mentions: These complex coefficients indicate that the reflected light may experience a phase shift3233343536444546. Under resonant conditions Δωc = Δωx = 0, the reflection coefficients /r/ and /r0/ are evaluated in Fig. 5, and the phase shifts θ and θ0 are evaluated in Fig. 6 inrelation to the decay ratios of cavity κs/κ and the cooperativity parameter C = g2/(κγ) of cavity QED5657, which is a geometric parameter that characterizes the absorptive, emissive, or dispersive coupling of an atom to the cavity mode. Based on Fig. 5, the reflection coefficients will satisfy /r/ ≈ 1 and /r0/ ≈ 1 when C ≫ 10 and κs/κ → 0, and these additional conditions are not required for relative phase shifts θ0 = π and θ = π because r and r0 are real under the resonant conditions Δωc = Δωx = 0. Hence, the real reflection coefficients r and r0 will be considered under the resonant conditions.

Bottom Line: We present implementations of a key quantum circuit: the three-qubit Toffoli gate.The three general controlled-NOT gates are involved using an auxiliary photon with two degrees of freedom.Our results show that photons and quantum spins may be used alternatively in quantum information processing.

View Article: PubMed Central - PubMed

Affiliation: Information Security and National Computing Grid Laboratory, Southwest Jiaotong University, Chengdu 610031, China.

ABSTRACT
Quantum computation offers potential advantages in solving a number of interesting and difficult problems. Several controlled logic gates, the elemental building blocks of quantum computer, have been realized with various physical systems. A general technique was recently proposed that significantly reduces the realization complexity of multiple-control logic gates by harnessing multi-level information carriers. We present implementations of a key quantum circuit: the three-qubit Toffoli gate. By exploring the optical selection rules of one-sided optical microcavities, a Toffoli gate may be realized on all combinations of photon and quantum spins in the QD-cavity. The three general controlled-NOT gates are involved using an auxiliary photon with two degrees of freedom. Our results show that photons and quantum spins may be used alternatively in quantum information processing.

No MeSH data available.


Related in: MedlinePlus