Fate of a Bose-Einstein condensate with attractive interaction

We calculate the decay amplitude of a harmonically trapped Bose-Einstein condensate with attractive interaction via the Feynman path integral. We find that when the number of particles is less than a critical number, the condensate decays relatively slowly through quantum tunneling. When the number exceeds the critical one, a "black hole" opens up at the center of the trap, in which density fluctuations become large due to a negative pressure, and collisional loss will drain the particles from the trap. As the black hole is fed by tunneling particles, we have a novel system in which quantum tunneling serves as a hydrodynamic source.Comment: 3 pages, REVTeX; email to [email protected] (Kerson Huang

Comment on ``Periodic wave functions and number of extended states in random dimer systems'

There are no periodic wave-functions in the RDM but close to the critical energies there exist periodic envelopes. These envelopes are given by the non-disordered properties of the system.Comment: RevTex file, 1 page, Comment X. Huang, X. Wu and C. Gong, Phys. Rev. B 55, 11018 (1997

Comment on "Critique and correction of the currently accepted solution of the infinite spherical well in quantum mechanics" by Huang Young-Sea and Thomann Hans-Rudolph

We comment on the paper "Critique and correction of the currently accepted solution of the infinite spherical well in quantum mechanics" by Huang Young-Sea and Thomann Hans-Rudolph, EPL 115, 60001 (2016) .Comment: 2 pages; Submitted to the Comments Section of EP

Multiple domestications of asian rice

In their recent Correspondence about our study showingthat there were three origins of Asian rice2, Huang and Han suggest that the methodology that we used to infer multiple domestications was flawed as it did not take account of the strong genetic bottleneck in japonica

Deep GrabCut for Object Selection

Most previous bounding-box-based segmentation methods assume the bounding box tightly covers the object of interest. However it is common that a rectangle input could be too large or too small. In this paper, we propose a novel segmentation approach that uses a rectangle as a soft constraint by transforming it into an Euclidean distance map. A convolutional encoder-decoder network is trained end-to-end by concatenating images with these distance maps as inputs and predicting the object masks as outputs. Our approach gets accurate segmentation results given sloppy rectangles while being general for both interactive segmentation and instance segmentation. We show our network extends to curve-based input without retraining. We further apply our network to instance-level semantic segmentation and resolve any overlap using a conditional random field. Experiments on benchmark datasets demonstrate the effectiveness of the proposed approaches.Comment: BMVC 201

PHONON COUPLING AND PHOTOIONIZATION CROSS-SECTIONS IN SEMICONDUCTORS

The coupling to lattice vibrations affects the photoionisation spectra of defects in semiconductors. This is especially important for deep defects. The effects are characterised mainly by a Huang-Rhys factor S0 and by a spectral moment. These are calculated for a variety of electron-photon coupling mechanisms as a function of the observable ionisation energy EI rather than the unobservable effective radius used by previous workers. For Frohlich coupling a good approximation for the Huang-Rhys factor is S0(x)/S0(0)=X/ square root ((5+x)/6) with x=EI/(effective Ryd for purely hydrogenic centre)