arXiv subjects

Jian-Wen Xu

Publications and source records attributed to Jian-Wen Xu.

7 recordsLinked to original sources

arXiv2026

Demonstration of Discrete-Time Quantum Walks and Observation of Topological Edge States in a Superconducting Qutrit Chain

Quantum walk serves as a versatile tool for universal quantum computing and algorithmic research. However, the implementation of discrete-time quantum walks (DTQWs) with superconducting circuits is still constrained by some limitations such as operation precision, circuit depth and connectivity. With improved hardware efficiency by using superconducting qutrits (three-level systems), we experimentally demonstrate a scalable DTQW in a superconducting circuit, observing the ballistic spreading of quantum walk in a qutrit chain. The usage of qutrits in our implementation allows hardware efficiently encoding of the walker position and the coin degree of freedom. By exploiting the flexibility and intrinsic symmetries of qutrit-based DTQWs, we successfully prepare two topological phases in the chain. For the first time, particle-hole-symmetry-protected edge states, bounded at the interface between these two topological phases, are observed in the superconducting platform. Measured parameter dependencies further validate the properties of edge states. The scalability and gate-control compatibility of the demonstrated DTQWs enable a versatile tool for superconducting quantum computing and quantum simulation.

quant-ph↗

arXiv2019

Theoretical $Σ$-$D$ Relations for Shell-Type Galactic Supernova Remnants

Relations between radio surface brightness ($Σ$) and diameter ($D$) of supernova remnants (SNRs) are important in astronomy. In this paper, following the work Duric \& Seaquist (1986) at adiabatic phase, we carefully investigate shell-type supernova remnants at radiative phase, and obtain theoretical $Σ$-$D$ relation at radiative phase of shell-type supernova remnants at 1 GHz. By using these theoretical $Σ$-$D$ relations at adiabatic phase and radiative phase, we also roughly determine phases of some supernova remnant from observation data.

astro-ph.HE↗

arXiv2014

Theoretical Derivation of $Σ$-$D$ Relation of Galactic SNRs

We derive the $Σ$-$D$ relation of Galactic supernova remnants of shell-type separately at adiabatic-phase and at radiative-phase through two sets of different formulas, considering the different physical processes of shell-type remnants at both stages. Also statistics on Galactic shell-type remnants about 57 was made. Then we do some comparison with other results obtained before. It shows that all the best fit lines in the $Σ$-$D$ relation plots newly are to some extent flatter than those derived by some authors at early time. Our theoretical and statistical outcomes are in somewhat good consistency.

astro-ph.HE↗

arXiv2009

A Unique Method to Determine SNe Initial Explosion Energy

There are several different methods to determine the individual supernovae (SNe) initial explosion energy, here we derive the average or typical explosion energy of shell-type supernova remnants (SNRs) in a particular way. By solving a group of equations pertaining to shell-type SNRs at the same stage we obtained some physical parameters, e.g. the distance ($d$), evolved age ($t$), etc.. Assuming series of different SN initial explosion energies ranging from $10^{48}$ ergs to $10^{53}$ ergs, we derived series of distance and age parameters with which compared already known ones. Thus the most likely value of the SNe initial explosion energy is obtained when the deviation is least, which equals to about $10^{51}$ ergs, in good agreement with the undertook value.

astro-ph.HE↗

arXiv2009

Statistics of Galactic Supernova Remnants (continued)

Our statistics on Galactic supernova remnants (SNRs) shows that the electrons temperature ($T$) of hard X-ray and the shock waves traveling velocity ($\upsilon$) decreases with ages ($t$) for all-sort remnants. However, the shock waves swept-up mass ($M_{su}$) of ISM increases with the age. Second, the remnant radio fluxes ($S$) at 1 GHz increase slightly with ISM electrons density ($n_0$). At last, the number distributions illustrate that the supernovae (SNe) initial kinetic energy ($E_0$), hydrogen column density ($N_H$), electrons temperature (kT) of hard X-ray, magnetic field ($B$) and the shock waves swept-up mass ($M_{su}$) of ISM mainly peaked at $(1 \sim 10) \times 10^{50}$ ergs, $(1 \sim 10)\times 10^{21}$ cm$^{-2}$, a few KeV, 100 $μ$G and 10$\sim$100 $M_{\odot}$, respectively.

astro-ph.HE↗

arXiv2009

Some Recent Progress on the Studies of Supernova Remnants

We briefly reviewed some recent progress on the studies of supernova remnants (SNRs), including the radio SNRs (the structure, polarization, spectrum etc.), observational characteristics of X-ray emission, pulsar wind nebulae (PWNe), association properties between SNR and PSR, interaction of SNR and interstellar medium (ISM), cosmos ray and the SNRs in external galaxies, etc.. Correspondingly to the continue improvement of space and spectrum resolution of the on-ground and in-space astronomical equipments at wavelengthes as radio, optical, X-ray and so on, we know about SNRs more and deeper.

astro-ph.HE↗

arXiv2009

Distances to Two Galactic Supernova Remnants: G32.8-0.1 and G346.6-0.2

There are either a near kinematic distance of 5.5 kpc or a far distance of 8.8 kpc for a Galactic supernova remnant (SNR) G32.8$-$0.1 derived by using the rotation curve of the Galaxy. Here we make sure that the remnant distance is the farther one 8.8 kpc through solving a group of equations for the shell-type remnants separately at the adiabatic-phase and the radiative-phase. For SNR G346.6$-$0.2 we determine its distance also the farther one 11 kpc rather than the nearer one 5.5 kpc.

astro-ph.HE↗