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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.


The amplified shifts of spin-dependent splitting in photon tunneling under the condition of horizontal (left column) and vertical polarizations (right column) with different potential barrier thicknesses: [(a), (b)] 9 nm, [(c), (d)] 12 nm, and [(e), (f)] 16 nm. represents the modified weak value of the weak measurements. The lines indicate the theoretical value and the circle, square, and triangle show the experimental data for three different areas of the tunneling sample (the error ranges are less than 10 μm).
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f4: The amplified shifts of spin-dependent splitting in photon tunneling under the condition of horizontal (left column) and vertical polarizations (right column) with different potential barrier thicknesses: [(a), (b)] 9 nm, [(c), (d)] 12 nm, and [(e), (f)] 16 nm. represents the modified weak value of the weak measurements. The lines indicate the theoretical value and the circle, square, and triangle show the experimental data for three different areas of the tunneling sample (the error ranges are less than 10 μm).

Mentions: We measure the amplified displacements varying with the postselection angles as shown in Fig. 4. To avoid the influence of surface quality factor of metal film, we carried out the experiments for three different areas of the tunneling sample. We prepare the metal (Au) tunneling potential barrier with three different thicknesses 9, 12, and 16 nm (See supplementary materials for confirming the actual thickness of tunneling barrier). After confirming the actual thickness of the metal tunneling potential barrier, we can observe the photonic SHE in this tunneling structure. For the preselection state /H〉, the initial transverse shifts are 9.1, 14.0, and 26.4 nm, respectively. For the preselection state /V〉, the initial transverse shifts are −5.4, −9.1, and −15.1 nm, respectively. We find that the transverse shifts are even larger than the potential barrier thickness. We also note that the weak value discussed here cannot be arbitrarily large when the overlap of preselection and postselection states is close to orthogonal. In fact, there exists the maximum output of the weak measurements, which is corresponding to the previous theoretical work32.


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

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

The amplified shifts of spin-dependent splitting in photon tunneling under the condition of horizontal (left column) and vertical polarizations (right column) with different potential barrier thicknesses: [(a), (b)] 9 nm, [(c), (d)] 12 nm, and [(e), (f)] 16 nm. represents the modified weak value of the weak measurements. The lines indicate the theoretical value and the circle, square, and triangle show the experimental data for three different areas of the tunneling sample (the error ranges are less than 10 μm).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: The amplified shifts of spin-dependent splitting in photon tunneling under the condition of horizontal (left column) and vertical polarizations (right column) with different potential barrier thicknesses: [(a), (b)] 9 nm, [(c), (d)] 12 nm, and [(e), (f)] 16 nm. represents the modified weak value of the weak measurements. The lines indicate the theoretical value and the circle, square, and triangle show the experimental data for three different areas of the tunneling sample (the error ranges are less than 10 μm).
Mentions: We measure the amplified displacements varying with the postselection angles as shown in Fig. 4. To avoid the influence of surface quality factor of metal film, we carried out the experiments for three different areas of the tunneling sample. We prepare the metal (Au) tunneling potential barrier with three different thicknesses 9, 12, and 16 nm (See supplementary materials for confirming the actual thickness of tunneling barrier). After confirming the actual thickness of the metal tunneling potential barrier, we can observe the photonic SHE in this tunneling structure. For the preselection state /H〉, the initial transverse shifts are 9.1, 14.0, and 26.4 nm, respectively. For the preselection state /V〉, the initial transverse shifts are −5.4, −9.1, and −15.1 nm, respectively. We find that the transverse shifts are even larger than the potential barrier thickness. We also note that the weak value discussed here cannot be arbitrarily large when the overlap of preselection and postselection states is close to orthogonal. In fact, there exists the maximum output of the weak measurements, which is corresponding to the previous theoretical work32.

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.