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Quantum interference induced photon blockade in a coupled single quantum dot-cavity system.

Tang J, Geng W, Xu X - Sci Rep (2015)

Bottom Line: The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field.Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system.This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing.

View Article: PubMed Central - PubMed

Affiliation: 1] Institute of Photo-electronic Thin Film Devices and Technology, Nankai University, Tianjin 300071, P. R. China [2] Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.

ABSTRACT
We propose an experimental scheme to implement a strong photon blockade with a single quantum dot coupled to a nanocavity. The photon blockade effect can be tremendously enhanced by driving the cavity and the quantum dot simultaneously with two classical laser fields. This enhancement of photon blockade is ascribed to the quantum interference effect to avoid two-photon excitation of the cavity field. Comparing with Jaynes-Cummings model, the second-order correlation function at zero time delay g((2))(0) in our scheme can be reduced by two orders of magnitude and the system sustains a large intracavity photon number. A red (blue) cavity-light detuning asymmetry for photon quantum statistics with bunching or antibunching characteristics is also observed. The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field. Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system. This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing.

No MeSH data available.


(a) The second-order correlation function in logarithmic scale (log10(g(2)(0))) and (b) the intracavity photon number nc as a function of cavity-light detuning Δc and Rabi Rabi coupling strength Ω for g = 2κ and θ/π = 0.082.
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f5: (a) The second-order correlation function in logarithmic scale (log10(g(2)(0))) and (b) the intracavity photon number nc as a function of cavity-light detuning Δc and Rabi Rabi coupling strength Ω for g = 2κ and θ/π = 0.082.

Mentions: Figure 5(a) and 5(b) show the contour plots of g(2)(0) and nc as a function of Δc and Ω with a fixed phase θopt/π = 0.082. As expected, a strong photon blockade should occur near the red detuning with Δc ≈ g. While for blue detuning with Δc ≈ −g, there is no strong blockade because the phase of 0.082π is not an optimized value in this case. Therefore, a higher intracavity photon number for blue detuning regime is expected as shown in Fig. 5(b). Note that at red detuning with Δc ≈ g, intracavity photon number nc is still much larger than the mean photon number nc = (η/κ)2 = 0.01 in an empty cavity at strong photon blockade regime. This means that this scheme can achieve an ideal single photon source using solid-state single quantum dots with a strong photon blockade and a large cavity output. In fact, a moderate QD-cavity coupling strength g is sufficient for this purpose, which means that we do not need high quality factors (Q) for the nanocavities. In addition, the calculations show that photon blockade effect can survive with a relatively large parameter variation. As a result, the robustness of photon blockade for single QDs does not need to perfectly satisfy the optimal QI conditions in Eq. (7), which should be more easily to be achieved experimentally. In certain regimes, g(2)(0) with strong super-Poissonian quantum statistics is also observed for off-resonant excitation at Δc ≈ 0.16g but with an ultra-low intracavity photon number nc = 1.613 × 10−5.


Quantum interference induced photon blockade in a coupled single quantum dot-cavity system.

Tang J, Geng W, Xu X - Sci Rep (2015)

(a) The second-order correlation function in logarithmic scale (log10(g(2)(0))) and (b) the intracavity photon number nc as a function of cavity-light detuning Δc and Rabi Rabi coupling strength Ω for g = 2κ and θ/π = 0.082.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4363868&req=5

f5: (a) The second-order correlation function in logarithmic scale (log10(g(2)(0))) and (b) the intracavity photon number nc as a function of cavity-light detuning Δc and Rabi Rabi coupling strength Ω for g = 2κ and θ/π = 0.082.
Mentions: Figure 5(a) and 5(b) show the contour plots of g(2)(0) and nc as a function of Δc and Ω with a fixed phase θopt/π = 0.082. As expected, a strong photon blockade should occur near the red detuning with Δc ≈ g. While for blue detuning with Δc ≈ −g, there is no strong blockade because the phase of 0.082π is not an optimized value in this case. Therefore, a higher intracavity photon number for blue detuning regime is expected as shown in Fig. 5(b). Note that at red detuning with Δc ≈ g, intracavity photon number nc is still much larger than the mean photon number nc = (η/κ)2 = 0.01 in an empty cavity at strong photon blockade regime. This means that this scheme can achieve an ideal single photon source using solid-state single quantum dots with a strong photon blockade and a large cavity output. In fact, a moderate QD-cavity coupling strength g is sufficient for this purpose, which means that we do not need high quality factors (Q) for the nanocavities. In addition, the calculations show that photon blockade effect can survive with a relatively large parameter variation. As a result, the robustness of photon blockade for single QDs does not need to perfectly satisfy the optimal QI conditions in Eq. (7), which should be more easily to be achieved experimentally. In certain regimes, g(2)(0) with strong super-Poissonian quantum statistics is also observed for off-resonant excitation at Δc ≈ 0.16g but with an ultra-low intracavity photon number nc = 1.613 × 10−5.

Bottom Line: The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field.Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system.This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing.

View Article: PubMed Central - PubMed

Affiliation: 1] Institute of Photo-electronic Thin Film Devices and Technology, Nankai University, Tianjin 300071, P. R. China [2] Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P. R. China.

ABSTRACT
We propose an experimental scheme to implement a strong photon blockade with a single quantum dot coupled to a nanocavity. The photon blockade effect can be tremendously enhanced by driving the cavity and the quantum dot simultaneously with two classical laser fields. This enhancement of photon blockade is ascribed to the quantum interference effect to avoid two-photon excitation of the cavity field. Comparing with Jaynes-Cummings model, the second-order correlation function at zero time delay g((2))(0) in our scheme can be reduced by two orders of magnitude and the system sustains a large intracavity photon number. A red (blue) cavity-light detuning asymmetry for photon quantum statistics with bunching or antibunching characteristics is also observed. The photon blockade effect has a controllable flexibility by tuning the relative phase between the two pumping laser fields and the Rabi coupling strength between the quantum dot and the pumping field. Moreover, the photon blockade scheme based on quantum interference mechanism does not require a strong coupling strength between the cavity and the quantum dot, even with the pure dephasing of the system. This simple proposal provides an effective way for potential applications in solid state quantum computation and quantum information processing.

No MeSH data available.