56 citations · 294 across the 14 of their papers we have counts for
14 papers
Multiparameter estimation for qubit states with collective measurements: a case study
Yink Loong Len
Quantum estimation involving multiple parameters remains an important problem of both theoretical and practical interest. In this work, we study the problem of simultaneous estimat…
Quantum metrology with imperfect measurements
Yink Loong Len, Tuvia Gefen, Alex Retzker +1
The impact of measurement imperfections on quantum metrology protocols has not been approached in a systematic manner so far. In this work, we tackle this issue by generalising fir…
Sub-Rayleigh characterization of a binary source by spatially demultiplexed coherent detection
Chandan Datta, Yink Loong Len, Karol Łukanowski +2
We investigate theoretically coherent detection implemented simultaneously on a set of mutually orthogonal spatial modes in the image plane as a method to characterize properties o…
Sub-Rayleigh resolution of two incoherent sources by array homodyning
Chandan Datta, Marcin Jarzyna, Yink Loong Len +3
Conventional incoherent imaging based on measuring the spatial intensity distribution in the image plane faces the resolution hurdle described by the Rayleigh diffraction criterion…
Resolution limits of spatial mode demultiplexing with noisy detection
Yink Loong Len, Chandan Datta, Michał Parniak +1
We consider the problem of estimating the spatial separation between two mutually incoherent point light sources using the super-resolution imaging technique based on spatial mode…
Reply to "Comment on `Past of a quantum particle revisited' "
Berthold-Georg Englert, Kelvin Horia, Jibo Dai +2
We stand by our findings in Phys. Rev A. 96, 022126 (2017). In addition to refuting the invalid objections raised by Peleg and Vaidman, we report a retrocausation problem inherent…
Open-System Quantum Error Correction
Yink Loong Len, Hui Khoon Ng
We study the performance of quantum error correction (QEC) on a system undergoing open-system (OS) dynamics. The noise on the system originates from a joint quantum channel on the…
Unambiguous path discrimination in a two-path interferometer
Yink Loong Len, Jibo Dai, Berthold-Georg Englert +1
When a photon is detected after passing through an interferometer one might wonder which path it took, and a meaningful answer can only be given if one has the means of monitoring…
Past of a quantum particle: Common sense prevails
Berthold-Georg Englert, Kelvin Horia, Jibo Dai +2
We analyze Vaidman's three-path interferometer with weak path marking [Phys. Rev. A 87, 052104 (2013)] and find that common sense yields correct statements about the particle's pat…
Airy-averaged gradient corrections for two-dimensional fermion gases
Martin-Isbjörn Trappe, Yink Loong Len, Hui Khoon Ng +1
Building on the discussion in PRA 93, 042510 (2016), we present a systematic derivation of gradient corrections to the kinetic-energy functional and the one-particle density, in pa…
Leading gradient correction to the kinetic energy for two-dimensional fermion gases
Martin-Isbjörn Trappe, Yink Loong Len, Hui Khoon Ng +2
Density functional theory (DFT) is notorious for the absence of gradient corrections to the two-dimensional (2D) Thomas-Fermi kinetic-energy functional; it is widely accepted that…
The initial system-bath state via the maximum-entropy principle
Jibo Dai, Yink Loong Len, Hui Khoon Ng
The initial state of a system-bath composite is needed as the input for prediction from any quantum evolution equation to describe subsequent system-only reduced dynamics or the no…
Experimental detection of entanglement with optimal-witness families
Jibo Dai, Yink Loong Len, Yong Siah Teo +2
We report an experiment in which one determines, with least tomographic effort, whether an unknown two-photon polarization state is entangled or separable. The method measures whol…
Controllable generation of mixed two-photon states
Jibo Dai, Yink Loong Len, Yong Siah Teo +2
We report a controllable method for producing mixed two-photon states via Spontaneous Parametric Down-Conversion with a two-type-I crystal geometry. By using variable polarization…