اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدElectronic Hong-Ou-Mandel interferometry in two-dimensional topological insulators
157
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The edge states of a two-dimensional topological insulator are characterized by their helicity, a very remarkable property which is related to the time-reversal symmetry and the topology of the underlying system. We theoretically investigate a Hong-Ou-Mandel like setup as a tool to probe it. Collisions of two electrons with the same spin show a Pauli dip, analogous to the one obtained in the integer quantum Hall case. Moreover, the collisions between electrons of opposite spin also lead to a dip, known as $mathbb{Z}_{2}$ dip, which is a direct consequence of the constraints imposed by time-reversal symmetry. In contrast to the integer quantum Hall case, the visibility of these dips is reduced by the presence of the additional edge channels, and crucially depends on the properties of the quantum point contact. As a unique feature of this system, we show the possibility of three-electron interference, which leads to a total suppression of the noise independently of the point contact configuration. This is assured by the peculiar interplay between Fermi statistics and topology. This work intends to extend the domain of applicability of electron quantum optics.
قيم البحث
اقرأ أيضاً
We propose a two-dimensional Hong-Ou-Mandel (HOM) type interference experiment for Weyl fermions in graphene and 3D topological insulators. Since Weyl fermions exhibit linear dispersion, similar to photons in vacuum, they can be used to obtain the HO
M interference intensity pattern as a function of the delay time between two Weyl fermions. We show that while the Coulomb interaction leads to a significant change in the angle dependence of the tunneling of two identical Weyl fermions incident from opposite sides of a potential barrier, it does not affect the HOM interference pattern, in contrast to previous expectations. We apply our formalism to develop a Weyl fermion beam-splitter (BS) for controlling the transmission and reflection coefficients. We calculate the resulting time-resolved correlation function for two identical Weyl fermions scattering off the BS.
The quantum statistics of atoms is typically observed in the behavior of an ensemble via macroscopic observables. However, quantum statistics modifies the behavior of even two particles, inducing remarkable consequences that are at the heart of quant
um science. Here we demonstrate near-complete control over all the internal and external degrees of freedom of two laser-cooled 87Rb atoms trapped in two optical tweezers. This full controllability allows us to implement a massive-particle analog of a Hong-Ou-Mandel interferometer where atom tunneling plays the role of a photon beamsplitter. We use the interferometer to probe the effect of quantum statistics on the two-atom dynamics under tunable initial conditions, chosen to adjust the degree of atomic indistinguishability. Our work thereby establishes laser-cooled atoms in optical tweezers as a new route to bottom-up engineering of scalable, low-entropy quantum systems.
We review and develop recent results regarding Leviton excitations generated in topological states of matter - such as integer and fractional quantum Hall edge channels - and carrying a charge multiple of the electronic one. The peculiar features ass
ociated to these clean and robust emerging excitations can be detected through current correlation measurements. In particular, relevant information can be extracted from the noise signal in generalized Hong-Ou-Mandel experiments, where Levitons with different charges collide against each other at a quantum point contact. We describe this quantity both in the framework of the photo-assisted noise formalism and in terms of a very interesting and transparent picture based on wave-packet overlap.
We consider the effect of dephasing on a quantum dot which injects single electrons on a chiral edge channel of the quantum Hall effect. Dephasing is described by the coupling of the dot to a bosonic bath which represents the electromagnetic environm
ent. Using the input-output formalism of quantum optics, we derive the density matrix of the edge degrees of freedom. Results are illustrated by computing the zero frequency current-current correlations when two such single electron emitters achieve a collision at the location of a quantum point contact, in the same spirit as the Hong Ou Mandel experiment of quantum optics. Such correlations are directly linked to the quantum mechanical purity. We show that as observed in a recent experiment, the effect of dephasing leads to a non-vanishing of the Hong Ou Mandel dip when the time delay between the two electron wave packets is zero. Generalizations to time filtered wave packets as well as to asymmetric, detuned injection between opposite edges are obtained.
Hong-Ou-Mandel (HOM) interference, i.e. the bunching of indistinguishable photons at a beam splitter is a staple of quantum optics and lies at the heart of many quantum sensing approaches and recent optical quantum computers. Although originally prop
osed as a method for sensing micron-scale variations in photon propagation path lengths and despite the detection of photon bunching using camera technologies, the technique is still to be extended to the imaging domain. We report a full-field, scan-free, quantum imaging technique that exploits HOM interference to reconstruct the surface depth profile of transparent samples. We measure both the bunched and anti-bunched photon-pair distributions at the HOM interferometer output which are combined to provide a lower-noise image of the sample. This approach demonstrates the possibility of HOM microscopy as a tool for label-free imaging of transparent samples in the very low photon regime.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
