“…( 68), we can see that the resonances take place at k ω = |ε 0 | ≈ ∆E. Multi-photon processes are being studied in various systems: superconducting qubits (Saito et al, 2004;Shevchenko et al, 2012b;Tornes and Stroud, 2008;Wallraff et al, 2003), two-dimensional electron systems (Zudov et al, 2006), atomic and molecular structures (Arbó et al, 2010), Rydberg atoms ( van Ditzhuijzen et al, 2009;Førre, 2004), TLSs in superconducting circuits (Burin et al, 2014), quantum dots (Giavaras and Tokura, 2019a,b), and electromechanical systems (Heinrich et al, 2010).…”