Photoinduced Phase Transitions

by Nasu, K.

• ISBN13: 9789812387639
• ISBN10: 9812387633
• Format: Hardcover
• Copyright: 2004-09-30
• Publisher: World Scientific Pub Co Inc

Summary

A new class of insulating solids was recently discovered. When irradiated by a few visible photons, these solids give rise to a macroscopic excited domain that has new structural electronic orders quite different from the starting ground state. This occurrence is called "photoinduced phase transition," and this multi-authored book reviews recent theoretical and experimental studies of this new phenomenon. Why and how do photoexcited few electrons finally result in an excited domain with a macroscopic size? How is the resultant photoinduced phase different from the ordinary thermal-induced phase? This review volume answers those essential questions.

Table of Contents

Chapter 1 Theories for Photoinduced Structural Phase Transitions and their Dynamics	1	(70)
Keiichiro Nasu
1 Equilibrium Phases, Nonequilibrium Phases and Photoinduced Phase Transitions	3	(1)
2 Relaxation of Optical Excitations, Hidden Multi-Stability and Photoinduced Phase Transitions	4	(3)
3 Photoinduced Ionic -> Neutral Phase Transition in Organic Molecular Crystal TTF-CA	7	(1)
4 Threshold Excitation Intensity and Initial Condition Sensitivity	8	(4)
5 Adiabatic Path of Photoinduced Ionic -> Neutral Phase Transition in TTF-CA Crystal	12	(16)
5.1 Model Hamiltonian	13	(3)
5.2 Ground state properties	16	(3)
5.3 Energy band structure and lowest excited state	19	(1)
5.4 Relaxation path	20	(7)
5.5 High energy optical excited states in SDW state	27	(1)
6 Early Time Nonlinear Nonequilibrium Quantum Dynamics and Initial Condition Sensitivity	28	(11)
6.1 Model Hamiltonian for quantum dynamics	31	(1)
6.2 Relaxation and occurrence or nonoccurrence of the PSPT	32	(1)
6.3 Life time prolongation	33	(1)
6.4 Iterative method for exciton proliferation	34	(3)
6.5 Numerical results	37	(2)
7 Difference between Photoinduced Nonequilibrium Phase and High Temperature Equilibrium Phase	39	(11)
7.1 Photoinduced phase transition in organo-metallic complex crystal	40	(2)
7.2 Broken symmetry only in photoinduced nonequilibrium phase	42	(1)
7:3 Two-dimensional extended Peierls-Hubbard model	43	(1)
7.4 Mean field theory and phase diagram	44	(3)
7.5 Photoinduced phase	47	(3)
7.6 Hysteresis and nonadiabatic effect	50	(1)
8 Photoinduced Macroscopic Parity Violation and Ferroelectricity	50	(16)
8.1 Large polaron, self-trapped polaron, linear and quadratic couplings	51	(1)
8.2 Recent optical experiments on SrTiO3 and soft-anharmonic T1u mode	52	(3)
8.3 Possible scenario	55	(1)
8.4 Model Hamiltonian	55	(3)
8.5 Variational method for polaron	58	(1)
8.6 Continuum approximation	58	(4)
8.7 Numerical results	62	(2)
8.8 Singlet bipolaron	64	(1)
8.9 Further softening and enhanced epsilon 1	64	(2)
9 Further Problems in Photoinduced Phase Transitions	66	(1)
Acknowledgements	67	(1)
References	67	(4)
Chapter 2 Time-Resolved Spectroscopy of the Dynamics of Photoinduced Ionic-to-Neutral Phase Transition in Tetrathiafulvalen-P-Chloranil Crystals	71	(46)
Katsumi Tanimura
1 Introduction	72	(8)
1.1 Photoinduced structural phase transitions	72	(2)
1.2 The transition between neutral and ionic phases in TTF-CA	74	(2)
1.3 Photoinduced NI transition in TTF-CA	76	(4)
2 State-sensitive and Non-linear Features of Photoinduced NI Transition	80	(5)
2.1 Threshold excitation density for metastable N-phase formation	80	(3)
2.2 The formation yield of N-phase domains vs. excitation intensity	83	(2)
3 Primary Steps in the Dynamics of Photoinduced NI Transition	85	(16)
3.1 Overview of the results of fs time-resolved spectroscopy	86	(5)
3.2 Quantitative results of three important characteristics in the dynamics	91	(7)
3.3 Phenomenological analysis of the temporal evolution of NI transition	98	(3)
4 Microscopic Mechanisms of the Primary Processes in the Dynamics	101	(9)
4.1 Precursor-forming process	102	(4)
4.2 Local proliferation of neutral domains	106	(2)
4.3 N-phase order formation	108	(1)
4.4 Oscillatory modulations in reflectivity changes	109	(1)
5 CT Excited State vs. Molecular Excited State	110	(2)
6 Photoinduced vs. Temperature-induced NI Transitions	112	(2)
Acknowledgments	114	(1)
References	114	(3)
Chapter 3 Study on the Cooperative Photoinduced Low-Spin to High-Spin State Conversion Processes	117	(44)
Osamu Sakai and Tetsuo Ogawa
1 Introduction	118	(5)
2 Formulation	123	(2)
2.1 Master equation and the ion-ion interaction	123	(2)
2.2 Transition probability	125	(1)
3 Temporal Evolution of LS Fraction based on Koshino-Ogawa's Approach	125	(3)
4 Monte Carlo Simulation	128	(5)
4.1 Method of simulation	128	(1)
4.2 Results in two-dimensional case	129	(3)
4.3 Three-dimensional case	132	(1)
5 Difference and Similarity with the Temperature Induced Transition	133	(4)
5.1 The Fokker-Planck equation	133	(1)
5.2 Rate equation for the LS fraction	134	(2)
5.3 Potential barrier and nucleation of HS domain	136	(1)
6 Miscellaneous Problems	137	(3)
6.1 The Zeeman field	137	(1)
6.2 Intermittent excitation	138	(1)
6.3 Interruption of excitation	139	(1)
7 Coupling with Volume Striction Modes	140	(4)
8 Macroscopic Phase Separation	144	(3)
8.1 MC results	144	(2)
8.2 Phase coexistence condition	146	(1)
9 De-pinning of Volume Striction	147	(11)
9.1 Model of de-pinning	147	(4)
9.2 Three-dimensional case	151	(1)
10 Summary and Discussion	152	(4)
10.1 Cooperative LS to HS transition	152	(3)
10.2 Characteristics of photoinduced phase transitions (PIPTs)	155	(1)
Acknowledgments	156	(2)
References	158	(3)
Chapter 4 Femtosecond Dynamics of the Photo-Induced Lattice Rearrangements in Quasi-One-Dimensional Halogen-Bridged Platinum Complexes	161	(36)
Tohru Suemoto, Shinichi Tomimoto and Taira Matsuoka
1 Introduction	162	(1)
2 Excited States in Platinum Complexes	163	(8)
3 Theoretical Background of the Relaxation Dynamics	171	(2)
4 Time-Resolved Measurements and Dynamics	173
5 Pt-Br System	171	(1)
6 Pt-Cl System	171	(10)
7 Pt-I System	181	(2)
8 Halogen Ion Dependence	183	(2)
9 Visualization of the Wave-Packet	185	(6)
10 Exciton Localization Process	191	(3)
Acknowledgments	194	(1)
References	194	(3)
Chapter 5 Monte Carlo Simulations on Ising-Like Models for Photoinduced Phase Transitions	197	(42)
Tohru Kawamoto and Shuji Abe
1 Ising-Like Model for Photoinduced Phase Transitions	198	(3)
2 Ising-Like Model for Spin-Crossover Complexes	201	(5)
2.1 Experimental facts	201	(3)
2.2 Internal entropy effect	204	(1)
2.3 Cooperative interactions	205	(1)
2.4 Photoinduced vs. thermally induced phases	206	(1)
3 Monte Carlo Simulation Method	206	(10)
3.1 Monte Carlo simulations for Ising-like models	206	(1)
3.2 Master equation	207	(2)
3.3 Transition rates	209	(1)
3.3.1 Thermal fluctuations	209	(4)
3.3.2 Quantum mechanical tunneling	213	(2)
3.3.3 Photoexcitation	215	(1)
3.4 Calculation procedure	215	(1)
4 Photoinduced Phase Transition in Uniform Systems	216	(8)
4.1 Stationary state under constant photoexcitation	216	(1)
4.2 Phase transition kinetics under photoexcitation	217	(3)
4.3 Dynamical phase transition	220	(4)
5 Photoinduced Phase Transitions in Combined Structures	224	(13)
5.1 Proposed model	224	(2)
5.2 Simulation results for superstructures	226	(1)
5.2.1 Symmetric superstructures	226	(6)
5.2.2 Generalization	232	(3)
5.3 Discussion	235	(2)
References	237	(2)
Chapter 6 Photoinduced Phase Transitions in One-Dimensional Correlated Electron Systems	239	(70)
Hiroshi Okamoto, Shin-ichiro Iwai and Hiroyuki Matsuzaki
1 Introduction	241	(6)
1.1 Fundamental feature of 1D correlated electron systems	241	(3)
1.2 Concepts of photoinduced phase transitions in 1D correlated electron systems	244	(3)
2 Ultrafast Photoinduced Transition from Mott Insulator to Metal in Halogen-Bridged Nickel-Chain Compound	247	(12)
2.1 Crystal and electronic structures of halogen-bridged nickel-chain compound	248	(1)
2.2 Change of electronic structure in two-dimensional cuprate by chemical carrier doping	249	(2)
2.3 Ultrafast insulator-metal transition observed in femtosecond pump-probe reflection spectroscopy	251	(7)
2.4 Relaxation dynamics of the photoinduced metallic state	258	(1)
3 Photoinduced Phase Transition in a Spin-Peierls System of Organic Radical Crystal, TTTA	259	(10)
3.1 Room-temperature optical and magnetic bistability in TTTA	260	(3)
3.2 Photoinduced phase transition in TTTA	263	(6)
4 Dynamical Aspects of Photoinduced IN and NI Transitions in TTF-CA	269	(22)
4.1 Dynamical aspect of photoinduced IN transition	272	(4)
4.2 Excitation energy dependence of photoinduced IN transition	276	(5)
4.3 Coherent oscillations in photoinduced IN transition	281	(6)
4.4 Dynamical aspect of photoinduced NI transition	287	(4)
5 Phase Control and Photoinduced Phase Transition in 1D Halogen-Bridged Binuclear Platinum Compound	291	(10)
5.1 Phase control in PtPtI chains	293	(4)
5.2 Pressure-induced phase transition in PtPtI chains	297	(2)
5.3 Photo-induced phase transition in PtPtI chains	299	(2)
6 Summary	301	(2)
Acknowledgments	303	(1)
References	304	(5)
Chapter 7 Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction	309	(34)
Hervé Cailleau, Eric Collet, Marylise Buron-Le Cointe, Marie-Hélène Lemée-Cailleau and Shin-ya Koshihara
1 Introduction	311	(2)
2 What X-Ray Scattering Can See of a Photoinduced Phase Transition Accompanied by Structural Changes?	313	(9)
2.1 Bragg diffraction from periodic lattice	314	(2)
2.2 Average structural state	316	(2)
2.3 Symmetry change	318	(2)
2.4 Dynamical physical photoinduced features	320	(2)
3 How Fast or Ultra-Fast Time-Resolved X-Ray Scattering Experiment Proceeds?	322	(6)
3.1 Fast and ultra-fast X-ray sources	322	(2)
3.2 Optical laser pump and X-ray probe techniques	324	(3)
3.3 X-ray probed volume vs. photo-excited part	327	(1)
4 First Fast or Ultra-Fast Time-Resolved X-Ray Diffraction Experiments	328	(12)
4.1 Fast probing of N-I photoinduced phase transition	328	(7)
4.2 Ultra-fast probing in hard condensed matter	335	(5)
5 Conclusion	340	(1)
Acknowledgments	340	(1)
References	341	(2)
Index	343