English
Related papers

Related papers: Detector Backaction on the Self-Consistent Bound S…

200 papers

Bound states in the continuum (BICs) have been extensively exploited to enhance light--matter interactions in metamaterials, yet their emergence and utility in multi-atom waveguide platforms remain far less explored. Here we study…

Quantum Physics · Physics 2025-12-09 Xiang Guo , Xiaojun Zhang , Mingzhu Weng , Qian Bin , Hao-di Liu , Hai-Jun Xing , Xin-You Lü , Zhihai Wang

We generate single-photon catalyzed coherent states (SPCCSs) by means of quantum-optical catalysis based on the beam splitter (BS) or the parametric amplifier (PA). These states are obtained in one of the BS (or PA) output channels if a…

Quantum Physics · Physics 2016-06-22 Xue-xiang Xu , Hong-chun Yuan

We study topological phenomena of quantum walks by implementing a novel protocol that extends the range of accessible properties to the eigenvalues of the walk operator. To this end, we experimentally realise for the first time a split-step…

Collective measurements can project a system into an entangled state with enhanced sensitivity for measuring a quantum phase, but measurement back-action has limited previous efforts to only modest improvements. Here we use a collective…

Bound states in the continuum (BICs), referring to spatially localized bound states with energies falling within the range of extended modes, have been extensively investigated in single-particle systems, leading to diverse applications in…

Mesoscale and Nanoscale Physics · Physics 2024-09-17 Na Sun , Weixuan Zhang , Hao Yuan , Xiangdong Zhang

The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control…

Detecting entanglement in many-body quantum systems is crucial but challenging, typically requiring multiple measurements. Here, we establish the class of states where measuring connected correlations in just $\textit{one}$ basis is…

Quantum Physics · Physics 2024-04-05 Roopayan Ghosh , Sougato Bose

A quantum point contact (QPC), a narrow region separating two wider electron reservoirs, is the standard building block of sub-micron devices, such as quantum dots - small boxes of electrons, and qubits - the proposed basic elements of…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Tomaz Rejec , Yigal Meir

We analyze the entanglement properties of spins (qubits) attached to the boundary of spin chains near quantum critical points, or to dissipative environments, near a boundary critical point, such as Kondo-like systems or the dissipative two…

Quantum Physics · Physics 2009-11-10 T. Stauber , F. Guinea

We discuss the possibility to generate, manipulate, and probe single spins in single-level quantum dots coupled to ferromagnetic leads. The spin-polarized currents flowing between dot and leads lead to a non-equilibrium spin accumulation,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Matthias Braun , Jürgen König , Jan Martinek

Strong electron and spin correlations in a double-quantum-dot (DQD) can give rise to different quantum states. We observe a continuous transition from a Kondo state exhibiting a single-peak Kondo resonance to another exhibiting a double…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. C. Chen , A. M. Chang , M. R. Melloch

The superposition of quantum states is one of the hallmarks of quantum physics, and clear demonstrations of superposition have been achieved in a number of quantum systems. However, mechanical systems have remained a challenge, with only…

Bound states in the continuum (BICs) are quantum states with normalizable wave functions and energies that lie within the continuous spectrum for which extended or dispersive states are also available. These special states, which have shown…

Mesoscale and Nanoscale Physics · Physics 2024-07-29 Ricardo Y. Díaz-Bonifaz , Carlos Ramírez

We have analyzed theoretically the operation of the Bayesian quantum feedback of a solid-state qubit, designed to maintain perfect coherent oscillations in the qubit for arbitrarily long time. In particular, we have studied the feedback…

Mesoscale and Nanoscale Physics · Physics 2010-04-05 Qin Zhang , Rusko Ruskov , Alexander N. Korotkov

Quantum mechanical scattering resonances for colliding particles occur when a continuum scattering state couples to a discrete bound state between them. The coupling also causes the bound state to interact with itself via the continuum and…

Quantum Gases · Physics 2018-11-22 Ryan Thomas , Matthew Chilcott , Eite Tiesinga , Amita B. Deb , Niels Kjærgaard

We analyze quantum interference and decoherence effects in single-molecule junctions both experimentally and theoretically by means of the mechanically controlled break junction technique and density-functional theory. We consider the case…

Mesoscale and Nanoscale Physics · Physics 2012-09-26 Stefan Ballmann , Rainer Härtle , Pedro B. Coto , Marcel Mayor , Mark Elbing , Martin R. Bryce , Michael Thoss , Heiko B. Weber

We report a zero-bias peak in the differential conductance of a Quantum Point Contact (QPC), which splits in an external magnetic field. The peak is observed over a range of device conductance values starting significantly below $2e^2/h$.…

Mesoscale and Nanoscale Physics · Physics 2011-08-22 Tai-Min Liu , Bryan Hemingway , Andrei Kogan , Steven Herbert , Michael Melloch

The sensitivity afforded by quantum sensors is limited by decoherence. Quantum error correction (QEC) can enhance sensitivity by suppressing decoherence, but it has a side-effect: it biases a sensor's output in realistic settings. If…

Quantum Physics · Physics 2022-04-20 Ivan Rojkov , David Layden , Paola Cappellaro , Jonathan Home , Florentin Reiter

Eigenstate-preserving multi-qubit parity measurements lie at the heart of stabilizer quantum error correction, which is a promising approach to mitigate the problem of decoherence in quantum computers. In this work we explore a…

Quantum Physics · Physics 2019-11-07 Patrick Huembeli , Simon E. Nigg

A quantum point contact (QPC) patterned on a two-dimensional electron gas is investigated with a scanning gate setup operated at a temperature of 300 mK. The conductance of the point contact is recorded while the local potential is modified…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 A. Pioda , S. Kicin , D. Brunner , T. Ihn , M. Sigrist , K. Ensslin , M. Reinwald , W. Wegscheider