Possible mechanisms of carrier localization, metal–insulator transitions and stripe formation in inhomogeneous hole-doped cuprates

Bosonization of Cooper pairs and novel Bose-liquid superconductivity and superfluidity in high-Tc cuprates and other exotic systems

“…At R c a c , the fermions cannot move from one Cooper pair to another one and the nonoverlapping Cooper pairs behave like bosons. The criterion for bosonization of polaronic Cooper pairs can be determined from the uncertainty relation [40] ∆x · ∆E ( ∆k) 2 2m p 1 2∆k…”

Distinctive Features of Metal-Insulator Transitions, Multiscale Phase Separation, and Related Effects in Hole-Doped Cuprates

“…It is well known [31,48] that the large-and small-polaron states in three-dimensional solids are separated by a potential barrier. If the height of a potential barrier is sufficiently high [54], the existence of small polarons in the bulk is unlikely. A self-trapped carrier is usually called a large polaron, when its size is larger than the lattice constant.…”

Carrier localization, Anderson transitions and stripe formation in hole-doped cuprates

“…Therefore, the ground states of such hole carriers are their self-trapped (i.e. localized extrinsic and intrinsic polaronic) states lying in the CT gap of the cuprates [13]. A large ionicity of the cuprates η = ε ∞ /ε 0 << 1 (where ε ∞ and ε 0 are the high-frequency and static dielectric constants, respectively) enhances the polar electron-phonon interaction and the tendency to polaron formation.…”

“…A large ionicity of the cuprates η = ε ∞ /ε 0 << 1 (where ε ∞ and ε 0 are the high-frequency and static dielectric constants, respectively) enhances the polar electron-phonon interaction and the tendency to polaron formation. Actually, the relevant charge carriers in hole-doped cuprates are large polarons [13,14,15,16] and the strong electron-phonon interactions are responsible for enhancement of the polaron mass m p = (2.0 − 3.0)m b [17] (where m b m e is the free electron mass). The formation of nearly small Frölich polaron [18] might be also relevant.…”

“…According to Ref. [13], the ground state energies or binding energies E ep of extrinsic polarons would increase rapidly with decreasing ε ∞ from 5 to 3 or with increasing η from 0 to 0.12 and are equal to E ep (0.11 − 0.18) eV (for ε ∞ = 3.5 − 4.5 and η = 0.12) and E ep (0.086 − 0.14) eV (for ε ∞ = 4 and η = 0 − 0.12). Whereas the binding energies E p of intrinsic polarons would decrease noticeably with increasing η from 0 to 0.12 (i.e.…”