TY - JOUR
T1 - CDW-Exciton condensate competition and a condensate driven force
AU - Özgün, Ege
AU - Hakioǧlu, Tuǧrul
N1 - Publisher Copyright:
©2016 The Physical Society of Japan.
PY - 2016/8/15
Y1 - 2016/8/15
N2 - We examine the competition between the charge-density wave (CDW) instability and the excitonic condensate (EC) in spatially separated layers of electrons and holes. The CDW and the EC order parameters (OPs), described by two different mechanisms and hence two different transition temperatures TcCDWand TcEC,are self-consistently coupled by a microscopic mean field theory. We discuss the results in our model specifically focusing on the transition-metal dichalcogenides which are considered as the most typical examples of strongly coupled CDW/EC systems with atomic layer separations where the electronic energy scales are large with the critical temperatures in the range TcEC∼ TcCDW∼ 100-200 K. An important consequence of this is that the excitonic energy gap, hence the condensed free energy, vary with the layer separation resulting in a new type of force FEC . We discuss the possibility of this force as the possible driver of the structural lattice deformation observed in some TMDCs with a particular attention on the 1T-TiSe2 below 200 K.
AB - We examine the competition between the charge-density wave (CDW) instability and the excitonic condensate (EC) in spatially separated layers of electrons and holes. The CDW and the EC order parameters (OPs), described by two different mechanisms and hence two different transition temperatures TcCDWand TcEC,are self-consistently coupled by a microscopic mean field theory. We discuss the results in our model specifically focusing on the transition-metal dichalcogenides which are considered as the most typical examples of strongly coupled CDW/EC systems with atomic layer separations where the electronic energy scales are large with the critical temperatures in the range TcEC∼ TcCDW∼ 100-200 K. An important consequence of this is that the excitonic energy gap, hence the condensed free energy, vary with the layer separation resulting in a new type of force FEC . We discuss the possibility of this force as the possible driver of the structural lattice deformation observed in some TMDCs with a particular attention on the 1T-TiSe2 below 200 K.
UR - http://www.scopus.com/inward/record.url?scp=84982706158&partnerID=8YFLogxK
U2 - 10.7566/JPSJ.85.084706
DO - 10.7566/JPSJ.85.084706
M3 - Article
AN - SCOPUS:84982706158
SN - 0031-9015
VL - 85
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
IS - 8
M1 - 084706
ER -