arXiv subjects

Wen-Jie Xu

Publications and source records attributed to Wen-Jie Xu.

4 recordsLinked to original sources

arXiv2026

Realizing Next-Nearest-Neighbor Coupling and Peierls Phase in Circuits

We really design the trimerized circuits for the non-Hermitian one-dimensional Su-Schrieffer-Heeger models. There are three models, the initial one just considers the nearest neighbor coupling, the enhanced one is extended to contain the next-nearest-neighbor coupling, and the final one is reenhanced by introducing the Peierls phase. We investigate the dynamics of the circuit Laplacians with respect to the models, find that the topological states appear in the initial model and the response intervals are substantially affected by the next-nearest-neighbor coupling channels and the Peierls phase. These results are practically demonstrated by numerical simulations and experimental measurements. As a conclusion, the trimerized circuits can provide an adjustable and simple platform to investigate new topological physical states.

quant-ph↗

arXiv2023

Quantum storage of entangled photons at telecom wavelengths in a crystal

The quantum internet -- in synergy with the internet that we use today -- promises an enabling platform for next-generation information processing, including exponentially speed-up distributed computation, secure communication, and high-precision metrology. The key ingredients for realizing such a global network are the distribution and storage of quantum entanglement. As ground-based quantum networks are likely to be based on existing fiber networks, telecom-wavelength entangled photons and corresponding quantum memories are of central interest. Recently, $\rm^{167}Er^{3+}$ ions have been identified as a promising candidate for an efficient, broadband quantum memory at telecom wavelength. However, to date, no storage of entangled photons, the crucial step of quantum memory using these promising ions, $\rm^{167}Er^{3+}$, has been reported. Here, we demonstrate the storage and recall of the entangled state of two telecom photons generated from an integrated photonic chip based on a silicon nitride micro-ring resonator. Combining the natural narrow linewidth of the entangled photons and long storage time of $\rm^{167}Er^{3+}$ ions, we achieve storage time of 1.936 $μ$s, more than 387 times longer than in previous works. Successful storage of entanglement in the crystal is certified by a violation of an entanglement witness with more than 23 standard deviations (-0.234 $\pm$ 0.010) at 1.936 $μ$s storage time. These results pave the way for realizing quantum networks based on solid-state devices.

quant-ph↗

arXiv2018

Testing the Universality of Free Fall at ${10^{ - 10}}$ level by Comparing the Atoms in Different Hyperfine States with Bragg Diffraction

We have performed a precision atomic interferometry experiment on testing the universality of free fall (UFF) considering atoms' spin degree of freedom. Our experiment employs the Bragg atom interferometer with $^{87}$Rb atoms either in hyperfine state $\left| {F = 1,{m_F} = 0} \right\rangle $ or $\left| {F = 2,{m_F} = 0} \right\rangle $, and the wave packets in these two states are diffracted in one pair of Bragg beams alternatively, which can help suppress the common-mode systematic errors. We have obtained an E$\rm{\ddot{o}}$tv$\rm{\ddot{o}}$s ratio $η= \left( { 0.9 \pm 2.7} \right) \times {10^{ - 10}}$, and set a new record on the precision with a nearly 5 times improvement. Our experiment gives stronger restrictions on the possible UFF breaking mechanism.

quant-ph↗

arXiv2015

Test of the universality of free fall with atoms in different spin Orientations

We report a test of the universality of free fall (UFF) related to spin-gravity coupling effects by comparing the gravity acceleration of the $^{87}$Rb atoms in $m_F=+1$ versus that in $m_F=-1$, where the corresponding spin orientations are opposite. A Mach-Zehnder-type atom interferometer is exploited to sequentially measure the free fall acceleration of the atoms in these two sublevels, and the resultant E$\rm{\ddot{o}}$tv$\rm{\ddot{o}}$s ratio determined by this work is ${η_S} =(-0.2\pm1.5)\times 10^{-5}$. The interferometer using atoms in $m_F=+1$ or $m_F=-1$ is highly sensitive to magnetic field inhomogeneity, which limits the current experimental precision of our UFF test. The work here provides a stepping stone for future higher precision UFF test related to different spin orientations on atomic basis.

physics.atom-ph↗