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Related papers: Proposal for THz lasing from a topological quantum…

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We propose a scheme for generation of continuous-wave THz radiation. The scheme requires a medium where three discrete states in a $\Lambda $ configuration can be selected, with the THz-frequency transition between the two lower metastable…

Quantum Physics · Physics 2009-10-31 E. A. Korsunsky , D. V. Kosachiov

In this article we review the thermoelectric properties of three terminal devices with Coulomb coupled quantum dots (QDs) as observed in recent experiments [1,2]. The system we consider consists of two Coulomb-blockade QDs one of which can…

Mesoscale and Nanoscale Physics · Physics 2016-11-17 Holger Thierschmann , Rafael Sánchez , Björn Sothmann , Hartmut Buhmann , Laurens W. Molenkamp

We use optical pump--THz probe spectroscopy at low temperatures to study the hot carrier response in thin Bi$_2$Se$_3$ films of several thicknesses, allowing us to separate the bulk from the surface transient response. We find that for…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 R. Valdés Aguilar , J. Qi , M. Brahlek , N. Bansal , A. Azad , J. Bowlan , S. Oh , A. J. Taylor , R. P. Prasankumar , D. A. Yarotski

When a two-dimensional electron gas is exposed to a perpendicular magnetic field and an in-plane electric field, its conductance becomes quantized in the transverse in-plane direction: this is known as the quantum Hall (QH) effect. This…

Topological photonics shows considerable promise in revolutionizing photonic devices through the use of topological phases, leading to innovations like topological lasers that enhance light control. One of recent breakthroughs is reducing…

Optics · Physics 2024-05-16 Guangtai Lu , Yasutomo Ota , Satoshi Iwamoto

Topological pumping of ultracold atomic gases has recently been demonstrated in two experiments (Nat. Phys. 12, 296; 12, 350 (2016)). Here we study the topological pumping of a single magnon in a dynamically controlled spin-dependent…

Quantum Gases · Physics 2019-01-18 Feng Mei , Gang Chen , Liantuan Xiao , Suotang Jia

Thin (6-7 quintuple layer) topological insulator Bi2Se3 quantum dot devices are demonstrated using ultrathin (2~4 quintuple layer) Bi2Se3 regions to realize semiconducting barriers which may be tuned from Ohmic to tunneling conduction via…

Mesoscale and Nanoscale Physics · Physics 2012-01-19 Sungjae Cho , Dohun Kim , Paul Syers , Nicholas P. Butch , Johnpierre Paglione , Michael S. Fuhrer

We outline here how strong light-matter interaction can be used to induce quantum phase transition between normal and topological phases in two-dimensional topological insulators. We consider the case of a HgTe quantum well, in which band…

Mesoscale and Nanoscale Physics · Physics 2017-11-17 Mehedi Hasan , Dmitry Yudin , Ivan Iorsh , Olle Eriksson , Ivan Shelykh

Transition metal dichalcogenides (TMDs) are optically active layered materials providing potential for fast optoelectronics and on-chip photonics. We demonstrate electrically driven single-photon emission from localised sites in tungsten…

The Teraherz (THz) photoresponse of a two-dimensional electron gas in the quantum Hall regime is investigated. We use a sample structure which is topologically equivalent to a Corbino geometry combined with a cross-gate technique. This…

Mesoscale and Nanoscale Physics · Physics 2009-11-28 Christian Notthoff , Kevin Rachor , Detlef Heitmann , Axel Lorke

Topological states of light open exciting possibilities in quantum photonics promising the topological protection of quantum entanglement. Here, we put forward an approach to realize the topological states of photon pairs mediated by the…

Mesoscale and Nanoscale Physics · Physics 2021-01-04 Andrei A. Stepanenko , Mark D. Lyubarov , Maxim A. Gorlach

Resonant tunneling diodes (RTDs) support room-temperature terahertz (THz) oscillation and simultaneous THz-band detection, enabling compact monostatic THz sensors for practical and cost-effective sensing applications. In this paper, we…

Topological photonics provides an ideal platform for demonstrating novel band topology concepts, which are also promising for robust waveguiding, communication and computation applications. However, many challenges such as extremely large…

Optics · Physics 2020-03-18 Wenjing Liu , Minsoo Hwang , Zhurun Ji , Yuhui Wang , Gaurav Modi , Ritesh Agarwal

The advance of topological photonics has heralded a revolution for manipulating light as well as for the development of novel photonic devices such as topological insulator lasers. Here, we demonstrate topological lasing of circular…

We demonstrate topological defect lasers in a GaAs membrane with embedded InAs quantum dots. By introducing a disclination to a square-lattice of elliptical air holes, we obtain spatially confined optical resonances with high quality…

The gapless surface states of topological insulators (TI) can potentially be used to detect and harvest low-frequency infrared light. Nonetheless, it was shown that significant surface photocurrents due to light with frequency below the…

Mesoscale and Nanoscale Physics · Physics 2015-12-23 Netanel H. Lindner , Aaron Farrell , Eran Lustig , Gil Refael , Felix von Oppen

We present a novel "linear combination of atomic orbitals"-type of approximation, enabling accurate electronic structure calculations for systems of up to 20 or more electronically coupled quantum dots. Using realistic single quantum dot…

Mesoscale and Nanoscale Physics · Physics 2021-03-10 Alexander Mittelstädt , Ludwig A. Th. Greif , Stefan T. Jagsch , Andrei Schliwa

Graphene quantum dots (GQDs) are more promising than other kinds of semiconductor QDs because of their photostability and biocompatibility in different applications such as bioimaging, biosensing and light emitting diodes (LEDs). In…

Topological materials provide a platform that utilizes the geometric characteristics of structured materials to control the flow of waves, enabling unidirectional and protected transmission that is immune to defects or impurities. The…

Excited states in single quantum dots (QDs) have been shown to be useful for spin state initialization and manipulation. For scalable quantum information processing it is necessary to have multiple spins interacting. Therefore, we present…