In order to find the optimum conditions for exciton and exciton polariton mediated superconductivity, we studied the attractive mechanism between electrons of a cooper pair mediated by the exciton and exciton polariton condensate. Interplay of phonon and excitonmediated superconductivity in. Cavitymediated electronphoton superconductivity andrea cavalleri. The intensity enhancement for excitonrelated pl bands is attributed to the exciton recombination rate increasing due to the realization of excitonpolariton effects in big size sic ncs of different polytypes 6hpsic with inclusions of 15r and 4hpsic. T ejedor 3 1 maxplanck institute for quantum optics, 85748, garc hing, germany.
The displacement q0 which characterizes the exciton phonon interaction has different observable interpretation for. Their high oscillator strength and large exciton binding energies make singlewalled carbon nanotubes swcnts highly promising materials for the investigation of strong lightmatter interactions in the near infrared and at room temperature. Initially, we were considering a strong coupling regime, where coulomb attraction of two electrons to one exciton leads to formation of charged bosonic quasipartices. The concept of superconductivity mediated by boseeinstein condensates of excitons or exciton polaritons has been first outlined in 2007.
Any material exhibiting these properties is a superconductor. As follows from the currentvoltage characteristics, at a doping level of. Excitonpolariton coupling and enhanced emission in sic. We consider a model microcavity where a quantum well with a twodimensional electron gas is sandwiched between two undoped quantum wells, where a polariton condensate is formed. Extraordinary exciton conductance induced by strong coupling johannes feist1, and francisco j. The general concept of super conductivity is that when certain metals are cooled to low temperature, the lattice. Optical spectra and electrical conductivity of silicondoped epitaxial gallium nitride layers with uncompensated donor concentrations n d n a up to 4. The decay, gain, and dephasing terms are assumed tobeoflindbladformlo.
Although it is an open dissipative system, many features of bosons in equilibrium. The superconductivity and magnetism groups research interests are centred around the properties of strongly correlated electron systems. Pdf ultrafast photocurrent measurements of bulkconduction induced spin hall effect in the topological insulator bi2se3 jekwan lee, sangwan sim, sungjun park, soohyun park, seungwan cho, sooun lee, hoil kim, jehyun kim, wooyoung shim, junsung kim, dohun kim, and hyunyong choi. Effects of spatial dispersion on exciton polariton dynamics in strained, highquality znse epilayers. Microscopic mechanism of surfactantmediated epitaxial growth of ge on si100 surfaces. Excitonmediated superconductivity nature materials. Timeresolved surface plasmon polariton coupled exciton. Polariton mediated energy transfer between organic dyes in a strongcoupled optical microcavity.
Cavitymediated electronphoton superconductivity oxford physics. Spin polarized semimagnetic excitonpolariton condensate. Forrest one of the most fundamental properties of both organic and inorganic semiconductors is charge mobility. This study suggests that excitonexciton annihilation is a loss process which can significantly increase the lasing threshold in polariton microcavities. The former can be considered as 5f 2 cef states and the latter as conduction band states.
We revisit the exciton mechanism of superconductivity in the framework of microcavity physics, replacing virtual excitons as a binding agent of cooper pairs by excitations of an exciton polariton boseeinstein condensate. Exciton spectra and electrical conductivity of epitaxial. Surface plasmon mediated strong excitonphoton coupling in semiconductor nanocrystals article in nano letters 101. Phonon mediated lattice deformation produces cavityfacilitated pairing of cooperpair forming. In literature 8, 9 one nd reports on layered metalinsulator. Determination of excitonphonon coupling elements in singlewalled carbon nanotubes by raman overtone analysis andrew p. This exciton polariton mechanism of super conductivity was studied theoretically in a model struc. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a.
Also, g is half the splitting between the lower polariton lp and upper polariton up at low density, and m is the total number of excitonic sites in the sample. Ensley, honghua hu, zhongan li, seihum jang, alex ky. Timeresolved surface plasmon polariton coupled exciton and biexciton emission yikuan wang, tianyu yang, mahshid pourmand, jacob j. A method to simulate 1d superlattices for interacting excitonpolariton gases in serially coupled cavities is also proposed. Exciton diffusion in disordered small molecules for organic photovoltaics. Effects of spatial dispersion on excitonpolariton dynamics in strained, highquality znse epilayers. Exciton phonon coupling then the above upper bounds become ab exciton polaritons in semiconductor nanostructures constitute a model system of quantum fluid of ultra light bose excitations in a drivendissipative situation. We revisit the exciton mechanism of superconductivity in the framework of microcavity physics, replacing virtual excitons as a binding agent of.
Nano letters vol 20, no 2 american chemical society. In contrast to polaritonmediated superconductivity. The correlation between the excitonphonon interaction and the electrical transport property for the asgrown and annealed zno epilayers were investigated. Here, v is the vibrational frequency, q is a normalized. From a quantumelectrodynamical lightmatter description. Polariton condensation with localized excitons and.
Yuerui lu supertransport of excitons in atomically thin organic semiconductors at the 2d quantum limit 14. Determination of exciton phonon coupling elements in singlewalled carbon nanotubes by raman overtone analysis andrew p. Sample thickness dependence of the exciton polariton. Due to the exchange interaction between the conduction and valence electrons in the n 1 yellow exciton state, the energy of the orthoexciton is. Part 6 realisation of excitonmediated superconductivity. Influence of dielectric environment on exciton and bi. Excitonpolariton mediated superconductivity fabrice p. The interplay of phonon and excitonmediated superconductivity in. Extraordinary exciton conductance induced by strong coupling. It has been unambiguously shown that the mobility in both of these.
Lasergenerated excitonpolariton condensates in transition metal dichalcogenide heterostructures may trigger. The phenomenon was discovered in 1911 by heike kamerlingh onnes kamerlingh onnes, heike, 18531. These values lead to dimensionless parameters m 10 3, and by design 0. To date, however, the existence of the quatron, predicted theoretically, 25 has not. Exciton phonon coupling then the above upper bounds become ab cleo.
Superconductivity is widely regarded as one of the great scientific discoveries of the 20th century. The integrated absorption coefficient increases as the sample thickness decreases and also has an oscillatory component with period 0. Robert schrieffer, which is known as the bcs theory. Bruce weisman,2 sergei tretiak,1 svetlana kilina,1 and stephen k. An excitonpolariton bolometer for terahertz radiation detection gg paschos, tch liew, z hatzopoulos, av. Spin polarized semimagnetic excitonpolariton condensate in magnetic eld mateusz krol 1, rafa mirek 1, katarzyna lekenta 1, jeanguy rousset 1, daniel stephan 1, micha nawrocki 1, micha matuszewski 2, jacek szczytko 1, wojciech pacuski 1, and barbara pietka 1 1 institute of experimental physics, faculty of physics, university of warsaw, ul.
This excitonpolariton mechanism of superconductivity was studied theoretically in a model struc. Zno is receiving renewed attention for wide bandgap device applications due to a number of advantages it presents in comparison with gan, e. Quantum simulation of strongly correlated manybody systems in a finite chain of coupled cavities and its experimental signature are studied via the exact diagonalization of the manybody hamiltonian. A microscopic theory of superconductivity was developed in 1957 by john bardeen, leon cooper and j. Plasmonic crystals for strong lightmatter coupling in. Tuominen, and marc achermann physics department, university of massachusetts amherst, 666 n. Surface plasmon mediated strong excitonphoton coupling in. Part 6 realisation of exciton mediated superconductivity. Polariton a polariton is a bosonic quasiparticle formed by an excitation, such as an exciton or plasmon coupled dressed with photons. Polaritonic chemistry molecular systems strongly coupled to light show the emergence of polaritonic states, which can change the chemical properties of the molecules.
Pdf nonlinear spectradispersion of quinolinium dyes using dualarm zscan trenton r. Excitonpolariton behaviour in bulk and polycrystalline zno. Superconductivity and magnetism university of warwick. Lasergenerated exciton polariton condensates in transition metal dichalcogenide heterostructures may trigger cooper pairing of electrons and induce hightemperature superconductivity. Zno received a great deal of attention in the 1950s1970s, when the fundamental optical and electronic properties were studied. One of the possible designs to evidence exciton polariton mediated superconductivity. Superconductivity is the set of physical properties observed in certain materials, wherein electrical resistance vanishes and from which magnetic flux fields are expelled. The central feature of the bcs theory is that two electrons in the superconductor are able to form a bound pair called a cooper pair if they somehow experience an attractive interaction between. Excitonpolariton mediated superconductivity eprints soton.
Microscopic mechanism of surfactant mediated epitaxial growth of ge on si100 surfaces. Bosefermi mixture formed by a cavity excitonpolariton condensate. Neil na semiconductor quantum optoelectronics group 39 summary the field of excitonpolariton vastly expanded in the past decade. Introduction superconductivity discovered in 1911 by onnes 9, is the. Super conductivity article about super conductivity by.
Dynamical conductivity in bloch oscillating semiconductor supersuperlattices sj allen, p. In contrast to polaritonmediated superconductivity 2022, where the glue for electron pairing is provided by the exchange of hybridized exciton. The concept of superconductivity mediated by boseeinstein condensates of excitons or excitonpolaritons has been first outlined in 2007. Polaritonsa hybrid of lightmatter oscillationscan originate in different physical phenomena. This study suggests that exciton exciton annihilation is a loss process which can significantly increase the lasing threshold in polariton microcavities. Hard to have a condensate at high temperatures difficult to measure conductivity in microcavities. Determination of excitonphonon coupling elements in. Sep 23, 2011 the intensity enhancement for exciton related pl bands is attributed to the exciton recombination rate increasing due to the realization of exciton polariton effects in big size sic ncs of different polytypes 6hpsic with inclusions of 15r and 4hpsic. The general concept of superconductivity is that when certain metals are cooled to low temperature, the lattice. The sample thickness dependence of the absorption coefficient of the yellow exciton 1s line of cu 2 o was investigated experimentally using present state of the art crystals. In nite conductivity implies that if a current were passed through the material during its. Superconductivity and other collective phenomena in a hybrid bose. Relationship between crystalline order and exciton diffusion length in molecular organic semiconductors by richard r.
From fitting of the boseeinstein approximation using emission parameters extracted from temperaturedependent photoluminescence spectra, it was found that the strength of excitonphonon coupling in the annealed zno epilayers is stronger. Shelykh3,4 1school of physics and astronomy, university of southampton, southampton, so171bj, united kingtom 2dipartimento di fisica, universita di roma tor vergata, 003 roma, italy 3science institute, university of iceland, dunhagi 3, is107, reykjavik, iceland. The superconductivity and magnetism group is part of condensed matter physics in the physics department at the university of warwick. Magneticexcitonmediated superconductivity in upd2al3. Superconductivity is a unique and powerful phenomenon of nature. The physics of semiconductors the physics of semiconductors.