Theory of photoinduced phase transitions in itinerant electron systems

Yonemitsu, Kenji; Nasu, Keiichirō

doi:10.1016/j.physrep.2008.04.008

Cited by 146 publications

(115 citation statements)

References 173 publications

Supporting

Mentioning

115

Contrasting

Order By: Relevance

“…Many examples of I-M transitions induced by the filling control (FC) and the bandwidth control (BC) have been reported in 3d transition metal oxides [2] and/or low dimensional organic conductors [3,4] (Figure 2a). In addition, photoexcitation can induce I-M transition [5][6][7][8][9][10][11][12][13][14][15][16] (Figure 2b). The photoinduced I-M transitions (PIMTs) are dynamic melting of the electron ordering in a Mott insulator and the CO insulator.…”

Section: Introductionmentioning

confidence: 99%

Photoinduced Phase Transitions in α-, θ-, and κ-type ET Salts: Ultrafast Melting of the Electronic Ordering

Iwai¹

2012

Crystals

View full text Add to dashboard Cite

Photoinduced phase transitions in organic compounds with strong electron correlation ET [bis(ethylenedithio)-tetrathiafulvalene)-based salts α-(ET) 2 I 3 , θ-(ET) 2 RbZn(SCN) 4 , κ-(d-ET) 2 Cu[N(CN) 2 Br] were discussed based, on time resolved optical pump-probe spectroscopy using ~150 fs mid-infrared pulse, 12 fs near infrared pulse, and sub-picosecond terahertz pulse. (i) In charge-ordered insulators α-(ET) 2 I 3 and θ-(ET) 2 RbZn(SCN) 4 , we captured ultrafast snapshots of charge dynamics i.e., immediate (ca. 15 fs) generation of a microscopic metallic state (or equivalently the microscopic melting of the charge order) which is driven by the coherent oscillation (period; 18 fs) of correlated electrons. Subsequently, condensation of the microscopic metallic state to the macroscopic scale occurs in α-(ET) 2 I 3 . However, in θ-(ET) 2 RbZn(SCN) 4 , such condensation is prevented by the large potential barrier reflecting the structural difference between the insulator and metal; (ii) In a Dimer-Mott insulator κ-(d-ET) 2 Cu[N(CN) 2 Br], photogeneration of the metallic state rises during ca. 1 ps that is much slower than the melting of charge order, because the photoinduced insulator to metal transition is driven by the intradimer molecular displacement in the dimer Mott insulator. The ultrafast dynamics of photoinduced insulator-metal transitions depend strongly on the molecular arrangement, reflecting various competing phases in the ET sheets.

show abstract

Section: Introductionmentioning

confidence: 99%

Photoinduced Phase Transitions in α-, θ-, and κ-type ET Salts: Ultrafast Melting of the Electronic Ordering

Iwai¹

2012

Crystals

View full text Add to dashboard Cite

show abstract

“…U ltrafast control of conduction and magnetic properties in strongly correlated systems [1][2][3] has been extensively studied from the perspective of photoinduced insulatorto-metal transitions, or, equivalently, the 'melting' of electronic orders (red arrow in Fig. 1a) in Mott insulators [4][5][6][7][8][9][10] , chargeordered (CO) systems [11][12][13][14] and charge/spin density wave materials 6,[15][16][17][18][19][20] .…”

mentioning

confidence: 99%

Optical freezing of charge motion in an organic conductor

et al. 2014

Self Cite

View full text Add to dashboard Cite

Dynamical localization, that is, reduction of the intersite electronic transfer integral t by an alternating electric field, E(o), is a promising strategy for controlling strongly correlated systems with a competing energy balance between t and the Coulomb repulsion energy. Here we describe a charge localization induced by the 9.3 MVcm À 1 instantaneous electric field of a 1.5 cycle (7 fs) infrared pulse in an organic conductor a-(bis[ethylenedithio]-tetrathiafulvalene) 2 I 3 . A large reflectivity change of 425% and a coherent charge oscillation along the time axis reflect the opening of the charge ordering gap in the metallic phase. This optical freezing of charges, which is the reverse of the photoinduced melting of electronic orders, is attributed to the B10% reduction of t driven by the strong, high-frequency (oZt/:) electric field.

show abstract

“…X-ray diffraction was performed on single crystals with typical sizes of 600 × 200 × 100 μm 3 . The diffraction experiments were carried out on a Xcalibur 3 four-circles diffractometer (Oxford Diffraction) equipped with a two-dimensional (2D) sapphire 3 CCD detector with Mo Kα radiation (λ = 0.71069Å).…”

Section: Methodsmentioning

confidence: 99%

“…During the last decade, the field of ultrafast photoinduced transformation has been expanding rapidly along diverse directions: correlated electrons, charge density waves, magnetism, molecular switching, etc. [1][2][3][4]. A typical example is provided by a quasi-one-dimensional quarter filled organic conductor (EDO-TTF) 2 PF 6 where EDO-TTF is the abbreviation of the electron donor (D) molecule ethylenedioxytetrathiafulvalene.…”

Section: Introductionmentioning

confidence: 99%

Local response to light excitation in the charge-ordered phase of(EDO−TTF)2SbF6

et al. 2015

View full text Add to dashboard Cite

The family of materials (EDO-TTF) 2 XF 6 represents quasi-one-dimensional quarter filled systems exhibiting insulator-to-metal (I-M) phase transition at thermal equilibrium. (EDO-TTF) 2 PF 6 is known to undergo a photoinduced I-M conversion with cooperative response to light excitation. Here we use femtosecond pump-probe experiments to study the photoresponse of (EDO-TTF) 2 SbF 6 made of a larger counteranion SbF 6 compared to the well studied (EDO-TTF) 2 PF 6 . In the early stage of the photoinduced process, we reveal a multicomponent coherent oscillating feature. The evolution of this feature with excitation density and temperature points to the local nature of the photoswitching in (EDO-TTF) 2 SbF 6 . At longer time scale, we did not detect the features associated with the transformation to the M phase, albeit observed in the PF 6 derivative. We propose a scenario whereby the bigger size of the counteranion in (EDO-TTF) 2 SbF 6 hinders the establishment of this transformation at macroscopic scale.

show abstract

Theory of photoinduced phase transitions in itinerant electron systems

Cited by 146 publications

References 173 publications

Photoinduced Phase Transitions in α-, θ-, and κ-type ET Salts: Ultrafast Melting of the Electronic Ordering

Photoinduced Phase Transitions in α-, θ-, and κ-type ET Salts: Ultrafast Melting of the Electronic Ordering

Optical freezing of charge motion in an organic conductor

Local response to light excitation in the charge-ordered phase of(EDO−TTF)2SbF6

Contact Info

Product

Resources

About