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Observation of spin Hall effect in photon tunneling via weak measurements.

Zhou X, Ling X, Zhang Z, Luo H, Wen S - Sci Rep (2014)

Bottom Line: Photonic spin Hall effect (SHE) manifesting itself as spin-dependent splitting escapes detection in previous photon tunneling experiments due to the fact that the induced beam centroid shift is restricted to a fraction of wavelength.This photonic SHE is attributed to spin-redirection Berry phase which can be described as a consequence of the spin-orbit coupling.These findings provide new insight into photon tunneling effect and thereby offer the possibility of developing spin-based nanophotonic applications.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China.

ABSTRACT
Photonic spin Hall effect (SHE) manifesting itself as spin-dependent splitting escapes detection in previous photon tunneling experiments due to the fact that the induced beam centroid shift is restricted to a fraction of wavelength. In this work, we report on the first observation of this tiny effect in photon tunneling via weak measurements based on preselection and postselection technique on the spin states. We find that the spin-dependent splitting is even larger than the potential barrier thickness when spin-polarized photons tunneling through a potential barrier. This photonic SHE is attributed to spin-redirection Berry phase which can be described as a consequence of the spin-orbit coupling. These findings provide new insight into photon tunneling effect and thereby offer the possibility of developing spin-based nanophotonic applications.

No MeSH data available.


Intensity of the cross-polarized components of the beam tunneling through the barrier when the preselection and postselection states are orthogonal.The initial states are chosen as horizontal (left column) and vertical polarizations (right column). [(a), (b)] Theoretical results; [(c), (d)] Experimental results. The incident angle is fixed to 45° and the potential barrier thickness is 12 nm.
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f3: Intensity of the cross-polarized components of the beam tunneling through the barrier when the preselection and postselection states are orthogonal.The initial states are chosen as horizontal (left column) and vertical polarizations (right column). [(a), (b)] Theoretical results; [(c), (d)] Experimental results. The incident angle is fixed to 45° and the potential barrier thickness is 12 nm.

Mentions: When the preselection and postselection states are orthogonal, i.e., Δ = 0, we can look forward to detecting the cross-polarized components, hence, to register the spin-dependent splitting22. The cross-polarized field distributions are described in Fig. 3. Here, we use the polarizer P1 to get the preselection state as /ψ1〉 = /H〉 or /V〉 and the second polarizer P2 to obtain the postselection state /ψ2〉 = /V〉 or /H〉, respectively. The cross components suggest that photons with opposite helicities accumulate at the opposite edges of the beam, and thereby provide a direct evidence of photonic SHE in tunneling. We note that this effect is very similar to another experiment about doing phase estimation30 and is in fact related to the inverse weak value31. By making the state overlap the smallest parameter, the mode splits into two and be used to estimate the complementary variable. It is also noted that there exists strong scattering background for preselection state /H〉 [Fig. 3(c)]. The main reason is that, under this condition, the surface plasmon resonance of metal can be excited and the corresponding reflected field changes.


Observation of spin Hall effect in photon tunneling via weak measurements.

Zhou X, Ling X, Zhang Z, Luo H, Wen S - Sci Rep (2014)

Intensity of the cross-polarized components of the beam tunneling through the barrier when the preselection and postselection states are orthogonal.The initial states are chosen as horizontal (left column) and vertical polarizations (right column). [(a), (b)] Theoretical results; [(c), (d)] Experimental results. The incident angle is fixed to 45° and the potential barrier thickness is 12 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260228&req=5

f3: Intensity of the cross-polarized components of the beam tunneling through the barrier when the preselection and postselection states are orthogonal.The initial states are chosen as horizontal (left column) and vertical polarizations (right column). [(a), (b)] Theoretical results; [(c), (d)] Experimental results. The incident angle is fixed to 45° and the potential barrier thickness is 12 nm.
Mentions: When the preselection and postselection states are orthogonal, i.e., Δ = 0, we can look forward to detecting the cross-polarized components, hence, to register the spin-dependent splitting22. The cross-polarized field distributions are described in Fig. 3. Here, we use the polarizer P1 to get the preselection state as /ψ1〉 = /H〉 or /V〉 and the second polarizer P2 to obtain the postselection state /ψ2〉 = /V〉 or /H〉, respectively. The cross components suggest that photons with opposite helicities accumulate at the opposite edges of the beam, and thereby provide a direct evidence of photonic SHE in tunneling. We note that this effect is very similar to another experiment about doing phase estimation30 and is in fact related to the inverse weak value31. By making the state overlap the smallest parameter, the mode splits into two and be used to estimate the complementary variable. It is also noted that there exists strong scattering background for preselection state /H〉 [Fig. 3(c)]. The main reason is that, under this condition, the surface plasmon resonance of metal can be excited and the corresponding reflected field changes.

Bottom Line: Photonic spin Hall effect (SHE) manifesting itself as spin-dependent splitting escapes detection in previous photon tunneling experiments due to the fact that the induced beam centroid shift is restricted to a fraction of wavelength.This photonic SHE is attributed to spin-redirection Berry phase which can be described as a consequence of the spin-orbit coupling.These findings provide new insight into photon tunneling effect and thereby offer the possibility of developing spin-based nanophotonic applications.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha 410082, China.

ABSTRACT
Photonic spin Hall effect (SHE) manifesting itself as spin-dependent splitting escapes detection in previous photon tunneling experiments due to the fact that the induced beam centroid shift is restricted to a fraction of wavelength. In this work, we report on the first observation of this tiny effect in photon tunneling via weak measurements based on preselection and postselection technique on the spin states. We find that the spin-dependent splitting is even larger than the potential barrier thickness when spin-polarized photons tunneling through a potential barrier. This photonic SHE is attributed to spin-redirection Berry phase which can be described as a consequence of the spin-orbit coupling. These findings provide new insight into photon tunneling effect and thereby offer the possibility of developing spin-based nanophotonic applications.

No MeSH data available.