text: F. Cinti(1,2,3), A. Rettori(2,3), and A. Cuccoli(2) 
  (1) Department of Physics, University of Alberta, Edmonton, Alberta, Canada T6G 2J1 
  (2)CNISM and Department of Physics, University of Florence, 50019 Sesto Fiorentino (FI), Italy. and 
  (3)CNR-INFM S3 National Research Center, I-41100 Modena, Italy 
  (Dated: June 8, 2022) 
  
  The properties of helical thin ﬁlms have been thoroughly investigated by classical Monte Carlo 
  simulations. The employed model assumes classical planar spins in a body-centered tetragonal 
  lattice, where the helical arrangement along the ﬁlm growth direction has been modeled by nearest 
  neighbor and next-nearest neighbor competing interactions, the minimal requirement to get helical 
  order. We obtain that, while the in-plane transition temperatures remain essentially unchanged with 
  respect to the bulk ones, the helical/fan arrangement is stabilized at more and more low temperature 
  when the ﬁlm thickness, n, decreases; in the ordered phase, increasing the temperature, a softening 
  of the helix pitch wave-vector is also observed. Moreover, we show also that the simulation data 
  around both transition temperatures lead us to exclude the presence of a ﬁrst order transition for all 
  analyzed sizes. Finally, by comparing the results of the present work with those obtained for other 
  models previously adopted in literature, we can get a deeper insight about the entwined role played 
  by the number (range) of interlayer interactions and surface eﬀects in non-collinear thin ﬁlms. 