Data from: Observing quantum-classical correspondence through optical path integrals
Data files
Apr 24, 2026 version files 6.89 MB
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fig3a.csv
487.06 KB
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fig3b.csv
785 B
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fig3c.csv
550.16 KB
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fig3d.csv
322 B
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fig4a1.csv
198.77 KB
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fig4a2.csv
198.23 KB
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fig4b1.csv
422 B
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fig4b2.csv
520 B
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figS1.csv
630 B
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figS2(a1).xlsx
1.35 MB
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figS2(a2).xlsx
1.36 MB
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figS2(a3).xlsx
1.34 MB
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figS2(a4).xlsx
1.37 MB
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figS2(b)-(d).csv
2.04 KB
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README.md
18.18 KB
May 21, 2026 version files 6.89 MB
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fig3a.csv
487.06 KB
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fig3b.csv
785 B
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fig3c.csv
550.16 KB
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fig3d.csv
322 B
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fig4a1.csv
198.77 KB
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fig4a2.csv
198.23 KB
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fig4b1.csv
422 B
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fig4b2.csv
520 B
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figS1.csv
630 B
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figS2(a1).xlsx
1.35 MB
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figS2(a2).xlsx
1.36 MB
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figS2(a3).xlsx
1.34 MB
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figS2(a4).xlsx
1.37 MB
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figS2(b)-(d).csv
2.04 KB
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README.md
18.15 KB
Abstract
The quantum-classical correspondence (QCC) describes how quantum systems recover classical behavior in the semiclassical limit. One of the crucial mechanisms to this correspondence is the concept of action, which governs dynamics in both classical mechanics and quantum path integrals. Despite its fundamental importance, direct experimental access to the action of individual quantum paths has remained elusive. Here, we experimentally propose and experimentally demonstrate a direct method to measure the action of quantum paths between fixed spacetime points, based on weak-value measurement techniques. By introducing and analyzing the spectrum of the norm of the action gradient, we identify not only single but also multiple stationary-action paths in systems exhibiting complex QCC. Using an optical setup that simulates photon propagation in free space and under an impulsive potential, we reconstruct pathwise actions and observe sharp dips in the spectrum that correspond precisely to classical trajectories. This work establishes a general framework for directly accessing the action, opening new avenues for experimentally exploring the QCC. This dataset supports the study "Data from: Observing quantum-classical correspondence through optical path integrals". It provides the experimental and processed data that enable full reproduction of the figures in the associated manuscript.
Dataset DOI: 10.5061/dryad.02v6wwqjg
Description of the data and file structure
Files and variables
File: fig3a.csv
Description: The measured actions for free space in three specific boundary conditions.
Variables
- j: Index of paths sorted by their associated action in ascending order. It is represented as the horizontal axis in Fig. 3(a).
- S_th(0,0): Theoretical results for the action of the paths with boundary conditions xi = 0 and xf = 0, presented as a blue solid line in Fig. 3(a) with the results given in units of πħ.
- S_exp(0,0)-M: Mean results for the measured action of the paths with boundary conditions xi = 0 and xf = 0, presented as blue circles in Fig. 3(a) with the results given in units of πħ.
- S_exp(0,0)-SD: Standard deviations for the measured action of the paths with boundary conditions xi = 0 and xf = 0, presented as a blue error bars in Fig. 3(a) with the results given in units of πħ.
- S_th(-10,10): Theoretical results for the action of the paths with boundary conditions xi = -10 and xf = 10, presented as a orange solid line in Fig. 3(a) with the results given in units of πħ.
- S_exp(-10,10)-M: Mean results for the measured action of the paths with boundary conditions xi = -10 and xf = 10, presented as orange squares in Fig. 3(a) with the results given in units of πħ.
- S_exp(-10,10)-SD: Standard deviations for the measured action of the paths with boundary conditions xi = -10 and xf = 10, presented as orange error bars in Fig. 3(a) with the results given in units of πħ.
- S_th(15,-15): Theoretical results for the action of the paths with boundary conditions xi = 15 and xf = -15, presented as a purple solid line in Fig. 3(a) with the results given in units of πħ.
- S_exp(15,-15)-M: Mean results for the measured action of the paths with boundary conditions xi = 15 and xf = -15, presented as purple triangles in Fig. 3(a) with the results given in units of πħ.
- S_exp(15,-15)-SD: Standard deviations for the measured action of the paths with boundary conditions xi = 15 and xf = -15, presented as purple error bars in Fig. 3(a) with the results given in units of πħ.
- j_subfigure: Index of 1000 least-action paths, sorted by their associated action in ascending order. They are represented as the horizontal axis in subfigure of Fig. 3(a).
- S_subfigure(0,0): Measured actions of 1000 least-action paths under boundary conditions xi = 0, xf = 0 from one experiment repetition. They are presented as blue circles in subfigure of Fig. 3(a) with the results given in units of πħ.
- S_subfigure(-10,10): Measured actions of 1000 least-action paths under boundary conditions xi = -10, xf = 10 from one experiment repetition. They are presented as orange squares in subfigure of Fig. 3(a) with the results given in units of πħ.
- S_subfigure(15,-15): Measured actions of 1000 least-action paths under boundary conditions xi = 15, xf = -15 from one experiment repetition. They are presented as purple triangles in subfigure of Fig. 3(a) with the results given in units of πħ.
File: fig3b.csv
Description: The identified classical paths with minimum action for free space in three specific boundary conditions.
Variables
- t: Evolution time, in units of ϵ= 15 mm/c, is represented as the horizontal axis in Fig. 3(b).
- xcl_th(15,-15): Theoretical results for a classical path under the boundary conditions xi = 15, xf = -15, presented as a purple solid line in Fig. 3(b) with the results given in units of δx = 5.73 μm.
- xcl_exp(15,-15)-M: Mean results for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=15, xf=-15. The results are given in units of δx=5.73μm and are presented as purple triangles in Fig. 3(b).
- xcl_exp(15,-15)-SD: Standard deviations for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=15, xf=-15. The results are given in units of δx=5.73μm** and are presented as purple error bars in Fig. 3(b).
- xcl_th(-10,10): Theoretical results for a classical path under the boundary conditions xi = -10, xf = 10, presented as a orange solid line in Fig. 3(b) with the results given in units of δx = 5.73 μm.
- xcl_exp(-10,10)-M: Mean results for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=-10, xf=10. The results are given in units of δx=5.73μm and are presented as orange squares in Fig. 3(b).
- xcl_exp(-10,10)-SD: Standard deviations for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=-10, xf=10. The results are given in units of δx=5.73μm** and are presented as orange error bars in Fig. 3(b).
- xcl_th(0,0): Theoretical results for a classical path under the boundary conditions xi = 0, xf = 0, presented as a blue solid line in Fig. 3(b) with the results given in units of δx = 5.73 μm.
- xcl_exp(0,0)-M: Mean results for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=0, xf=0. The results are given in units of δx=5.73μm and are presented as blue circles in Fig. 3(b).
- xcl_exp(0,0)-SD: Standard deviations for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=0, xf=0. The results are given in units of δx=5.73μm and are presented as blue error bars in Fig. 3(b).
- xcl_exp(15,-15)-Smin: Paths derived with minimum of the measured action under the boundary conditions xi = 15, xf = -15, presented as a purple dashed line in Fig. 3(b) with the results given in units of δx = 5.73 μm.
- xcl_exp(-10,10)-Smin: Paths derived with minimum of the measured action under the boundary conditions xi =-10, xf = 10, presented as a orange dashed line in Fig. 3(b) with the results given in units of δx = 5.73 μm.
- xcl_exp(0,0)-Smin: Paths derived with minimum of the measured action under the boundary conditions xi =0, xf = 0, presented as a blue dashed line in Fig. 3(b) with the results given in units of δx = 5.73 μm.
File: fig3c.csv
Description: The norm of action gradient spectrum for free space in three specific boundary conditions.
Variables
- S(0,0): Measured actions of 10,000 paths with the smallest norm of action gradient (NAG) under boundary conditions xi = 0 and xf = 0. The results are presented Fig. 3(c1) and are given in units of πħ.
- S_NAG(0,0): 10,000 smallest NAG values of paths under boundary conditions xi = 0 and xf = 0. The results are presented Fig. 3(c1) and are given in units of πħ/δx.
- S(-10,10): Measured actions of 10,000 paths with the smallest norm of action gradient (NAG) under boundary conditions xi = -10 and xf = 10. The results are presented Fig. 3(c2) and are given in units of πħ.
- S_NAG(-10.10): 10,000 smallest NAG values of paths under boundary conditions xi = -10 and xf = 10. The results are presented Fig. 3(c2) and are given in units of πħ/δx.
- S(15,-15): Measured actions of 10,000 paths with the smallest norm of action gradient (NAG) under boundary conditions xi = 15 and xf = -15. The results are presented Fig. 3(c3) and are given in units of πħ.
- S_NAG(15,-15): 10,000 smallest NAG values of paths under boundary conditions xi = 15 and xf = -15. The results are presented Fig. 3(c3) and are given in units of πħ/δx.
File: fig3d.csv
Description: Identified paths from Fig.3(c).
Variables
- t: Evolution time, in units of ϵ= 15 mm/c, is represented as the horizontal axis in Fig. 3(d).
- xcl_th(15,-15): Theoretical results for a classical path under the boundary conditions xi = 15, xf = -15, presented as purple solid line in Fig. 3(d) with the results given in units of δx = 5.73 μm.
- xcl_NAG(15,-15)-R1: Identified path from the NAG spectrum under the boundary conditions xi = 15, xf = -15, presented as purple triangles in Fig. 3(d) with the results given in units of δx = 5.73 μm.
- xcl_th(-10,10): Theoretical results for a classical path under the boundary conditions xi = -10, xf = 10, presented as orange solid line in Fig. 3(d) with the results given in units of δx = 5.73 μm.
- xcl_NAG(-10,10)-R2: Identified path from the NAG spectrum under the boundary conditions xi = -10, xf = 10, presented as orange squares in Fig. 3(d) with the results given in units of δx = 5.73 μm.
- xcl_th(0,0): Theoretical results for a classical path under the boundary conditions xi = 0, xf = 0, presented as a blue solid line in Fig. 3(d) with the results given in units of δx = 5.73 μm.
- xcl_NAG(0,0)-R3-M: Mean values of identified paths from the NAG spectrum under the boundary conditions xi = 0, xf = 0, presented as blue circles in Fig. 3(d) with the results given in units of δx = 5.73 μm.
- xcl_NAG(0,0)-R3-SD: Standard deviations of identified paths from the NAG spectrum under the boundary conditions xi = 0, xf = 0, presented as blue circles in Fig. 3(d) with the results given in units of δx = 5.73 μm.
File: fig4a1.csv
Description: Experimental NAG spectra for an impulsive potential with boundary conditions xi = 0 and xf = 0.
Variables
- S(0,0): Measured actions of 10,000 paths with the smallest norm of action gradient (NAG) under boundary conditions xi = 0 and xf = 0. The results are presented Fig. 4(a1) and are given in units of πħ.
- S_NAG(0,0): 10,000 smallest NAG values of paths under boundary conditions xi = 0 and xf = 0. The results are presented Fig. 4(a1) and are given in units of πħ/δx.
File: fig4a2.csv
Description: Experimental NAG spectra for an impulsive potential with boundary conditions xi = -7 and xf = 5.
Variables
- S(-7,5): Measured actions of 10,000 paths with the smallest norm of action gradient (NAG) under boundary conditions xi = -7 and xf = 5. The results are presented Fig. 4(2) and are given in units of πħ.
- S_NAG(-7,5): 10,000 smallest NAG values of paths under boundary conditions xi = -7 and xf = 5. The results are presented Fig. 4(a2) and are given in units of πħ/δx.
File: fig4b1.csv
Description: Corresponding classical paths derived from the data in Fig.4(a1).
Variables
- t: Evolution time, in units of ϵ= 15 mm/c, is represented as the horizontal axis in Fig. 4(b1).
- xcl_th(0,0)-s1: Theoretical result for the first classical path solution under boundary conditions xi = 0, xf = 0, shown as the lower blue solid line in Fig. 4(b1) in units of δx = 5.73 μm.
- xcl_NAG(0,0)-R1: Identified path from region R1 of the NAG spectrum under the boundary conditions xi = 0, xf = 0, presented as green squares in Fig. 4(b1) with the results given in units of δx = 5.73 μm.
- xcl_th(0,0)-s2: Theoretical result for the second classical path solution under boundary conditions xi = 0, xf = 0, shown as the upper blue solid line in Fig. 4(b1) in units of δx = 5.73 μm.
- xcl_NAG(0,0)-R2: Identified path from region R2 of the NAG spectrum under the boundary conditions xi = 0, xf = 0, presented as purple triangles in Fig. 4(b1) with the results given in units of δx = 5.73 μm.
- xcl_NAG(0,0)-R3_1: The first identified path from region R3 of the NAG spectrum under the boundary conditions xi = 0, xf = 0, presented as pink crosses in Fig. 4(b1) with the results given in units of δx = 5.73 μm.
- xcl_NAG(0,0)-R3_2: The second identified path from region R3 of the NAG spectrum under the boundary conditions xi = 0, xf = 0, presented as pink diagonal crosses in Fig. 4(b1) with the results given in units of δx = 5.73 μm.
- xcl_Smin(0,0)-M: Mean results for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=0, xf=0. The results are given in units of δx=5.73μm and are presented as orange circles in Fig. 4(b1).
- xcl_Smin(0,0)-SD: Standard deviations for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=0, xf=0. The results are given in units of δx=5.73μm and are presented as orange error bars in Fig. 4(b1).
File: fig4b2.csv
Description: Corresponding classical paths derived from the data in Fig.4(a2).
Variables
- t: Evolution time, in units of ϵ= 15 mm/c, is represented as the horizontal axis in Fig. 4(b2).
- xcl_th(-7,5)-s1: Theoretical result for the first classical path solution under boundary conditions xi = -7, xf = 5, shown as the lower blue solid line in Fig. 4(b2) in units of δx = 5.73 μm.
- xcl_NAG(-7,5)-R1_1: The first identified path from region R1 of the NAG spectrum under the boundary conditions xi = -7, xf = 5, presented as green squares in Fig. 4(b2) with the results given in units of δx = 5.73 μm.
- xcl_NAG(-7,5)-R1_2: The second identified path from region R1 of the NAG spectrum under the boundary conditions xi = -7, xf = 5, presented as green diamonds in Fig. 4(b2) with the results given in units of δx = 5.73 μm.
- xcl_th(-7,5)-s2: Theoretical result for the second classical path solution under boundary conditions xi = -7, xf = 5, shown as the upper blue solid line in Fig. 4(b2) in units of δx = 5.73 μm.
- xcl_NAG(-7,5)-R2_1: The first identified path from region R2 of the NAG spectrum under the boundary conditions xi = -7, xf = 5, presented as upward triangles in Fig. 4(b2) with the results given in units of δx = 5.73 μm.
- xcl_NAG(-7,5)-R2_2: The second identified path from region R2 of the NAG spectrum under the boundary conditions xi = -7, xf = 5, presented as downward triangles in Fig. 4(b2) with the results given in units of δx = 5.73 μm.
- xcl_NAG(-7,5)-R3_1: The first identified path from region R3 of the NAG spectrum under the boundary conditions xi = -7, xf = 5, presented as pink crosses in Fig. 4(b2) with the results given in units of δx = 5.73 μm.
- xcl_NAG(-7,5)-R3_2: The second identified path from region R3 of the NAG spectrum under the boundary conditions xi = -7, xf = 5, presented as pink diagonal crosses in Fig. 4(b2) with the results given in units of δx = 5.73 μm.
- xcl_Smin(-7,5)-M: Mean results for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=-7, xf=5. The results are given in units of δx=5.73μm and are presented as orange circles in Fig. 4(b2).
- xcl_Smin(-7,5)-SD: Standard deviations for paths with measured action within the range [Smin,Smin+ε], under the boundary conditions xi=-7, xf=5. The results are given in units of δx=5.73μm and are presented as orange error bars in Fig. 4(b2).
File: figS1.csv
Description: Experimental produced potential.
Variables
- x: Position at moment tm, in units of δx=5.73μm, is represented as the horizontal axis in Fig. S1.
- V_m_th: Theoretical potential curve in units of πħ, is represented as solid lines in Fig. S1.
- V_m_exp: Measured results of potential curve in units of πħ, is represented as circles with dashed lines in Fig. S1.
File: figS2(a1).xlsx
Description: The first column and the first row of the table represent the coordinates xk and yk, respectively, in units of δx. The remaining values indicate the grayscale values of the grayscale image obtained by projecting onto the polarization basis |D⟩.
File: figS2(a2).xlsx
Description: The first column and the first row of the table represent the coordinates xk and yk, respectively, in units of δx. The remaining values indicate the grayscale values of the grayscale image obtained by projecting onto the polarization basis |A⟩.
File: figS2(a3).xlsx
Description: The first column and the first row of the table represent the coordinates xk and yk, respectively, in units of δx. The remaining values indicate the grayscale values of the grayscale image obtained by projecting onto the polarization basis |R⟩.
File: figS2(a4).xlsx
Description: The first column and the first row of the table represent the coordinates xk and yk, respectively, in units of δx. The remaining values indicate the grayscale values of the grayscale image obtained by projecting onto the polarization basis |L⟩.
File: figS2(b)-(d).csv
Description: Sample results from the action measurements.
Variables
- x_k: Position at moment tk, in units of δx=5.73μm, is represented as the horizontal axis in Fig. S2(b)-(d).
- P_A: Projected intensities on polarization basis |A⟩ after integration along the y-direction. The results are presented Fig. 4(b2) and are given in arbitrary units.
- P_D: Projected intensities on polarization basis |D⟩ after integration along the y-direction. The results are presented Fig. 4(b1) and are given in arbitrary units.
- P_L: Projected intensities on polarization basis |L⟩ after integration along the y-direction. The results are presented Fig. 4(b4) and are given in arbitrary units.
- P_R: Projected intensities on polarization basis |R⟩ after integration along the y-direction. The results are presented Fig. 4(b3) and are given in arbitrary units.
- Sigma_x: Expectation values of operator σx. The results are presented Fig. 4(c1) and are given in arbitrary units.
- Sigma_y: Expectation values of operator σy. The results are presented Fig. 4(c1) and are given in arbitrary units.
- S(x_k): The measured incremental actions as a function of xk. The results are presented Fig. 4(d) and are given in unit of πħ.
