arXiv subjects

D. Jin

Publications and source records attributed to D. Jin.

5 recordsLinked to original sources

arXiv2025

NbTiN Nanowire Resonators for Spin-Photon Coupling on Solid Neon

Electrons floating on a solid neon exhibit long charge coherence times, making them attractive for hybrid quantum systems. When combined with high-quality, high-impedance superconducting resonators and a local magnetic field gradient, this platform enables strong charge--photon and spin--charge coupling-key ingredients for scalable spin qubit architectures. In this work, we demonstrate that NbTiN nanowire resonators maintain high quality factors around 10^5 after depositing solid neon onto the resonators and subsequently loading electrons onto the neon surface, validating their suitability for electrons-on-neon platforms. Building on these experimental results, we theoretically analyze micromagnet designs and coupling strategies that can enable spin-photon interactions in this platform. Our analysis outlines performance targets for next-generation devices, showing that, at the charge sweet spot, spin qubit gate fidelities exceeding 99.99% for single-qubit operations and 99.9% for two-qubit operations are achievable with natural neon.

cond-mat.mes-hall↗

arXiv2018

The origin of the first neutron star -- neutron star merger

The first neutron star-neutron star (NS-NS) merger was discovered on August 17, 2017 through gravitational waves (GW170817) and followed with electromagnetic observations. This merger was detected in an old elliptical galaxy with no recent star formation. We perform a suite of numerical calculations to understand the formation mechanism of this merger. We probe three leading formation mechanisms of double compact objects: classical isolated binary star evolution, dynamical evolution in globular clusters and nuclear cluster formation to test whether they are likely to produce NS-NS mergers in old host galaxies. Our simulations with optimistic assumptions show current NS-NS merger rates at the level of 10^-2 yr^-1 from binary stars, 5 x 10^-5 yr^-1 from globular clusters and 10^-5 yr^-1 from nuclear clusters for all local elliptical galaxies (within 100 Mpc^3). These models are thus in tension with the detection of GW170817 with an observed rate 1.5 yr^-1 (per 100 Mpc^3; LIGO/Virgo estimate). Our results imply that either (i) the detection of GW170817 by LIGO/Virgo at their current sensitivity in an elliptical galaxy is a statistical coincidence; or that (ii) physics in at least one of our three models is incomplete in the context of the evolution of stars that can form NS-NS mergers; or that (iii) another very efficient (unknown) formation channel with a long delay time between star formation and merger is at play.

astro-ph.HE↗

arXiv2006

Evidence of s-wave pairing symmetry in layered superconductor Li$_{0.68}$NbO$_2$ from the specific heat measurement

A high quality superconducting Li$_{0.68}$NbO$_2$ polycrystalline sample was synthesized by deintercalation of Li ions from Li$_{0.93}$NbO$_2$. The field dependent resistivity and specific heat were measured down to 0.5 K. The upper critical field $H_{c2} (T)$ is deduced from the resistivity data and $H_{c2}(0)$ is estimated to be $\sim 2.98$ T. A notable specific heat jump is observed at the superconducting transition temperature $T_c \sim 5.0$ K at zero field. Below $T_c$, the electronic specific heat shows a thermal activated behavior and agrees well with the theoretical result of the BCS s-wave superconductors. It indicates that the superconducting pairing in Li$_{0.68}$NbO$_2$ has s-wave symmetry.

cond-mat.supr-con↗

arXiv2005

In-plane substitution effect on the magnetic properties of two-dimensional Spin-gap system SrCu$_2$(BO$_3$)$_2$

A series of in-plane substituted compounds, including Cu-site (SrZn$_x$Cu$_{2-x}$(BO$_3$)$_2$), and B-site (SrCu$_2$(Si$_x$B$_{1-x}$O$_3$)$_2$) substitution, were synthesized by solid state reaction. X-ray diffraction measurements reveal that these compounds are single-phase materials and their in-plane lattice parameter depends systematically on the substituting content $x$. The magnetic susceptibility in different magnetic fields, the magnetization at different temperatures, and the resistivity at room temperature were measured, respectively. It is found that the spin gap deduced from the magnetic susceptibility measurements decreases with increasing of $x$ in both Cu- and B-site substitution. No superconductivity was found in these substituted compounds.

cond-mat.str-el↗

arXiv2004

Doping Effects on the two-dimensional Spin Dimer Compound $SrCu_2(BO_3)_2$

A series of compounds M$_{0.1}$Sr$_{0.9}$Cu$_2$(BO$_3$)$_2$ with Sr substituted by M=Al, La, Na and Y were prepared by solid state reaction. XRD analysis showed that these doping compounds are isostructural to SrCu$_2$(BO$_3$)$_2$. The magnetic susceptibility from 1.9K to 300K in an applied magnetic field of 1.0T and the specific heat from 1.9K to 25K in applied fields up to 14T were measured. The spin gap is deduced from the low temperature susceptibility as well as the specific heat. It is found that the spin gap is strongly suppressed by magnetic fields. No superconductivity is observed in all four samples.

cond-mat.str-el↗