Hysteretic Current–Voltage Characteristics in the Deuterium-Dynamics-Triggered Charge-Ordered Phase of κ-D₃(Cat-EDT-TTF)₂

Molecular quantum materials: electronic phases and charge dynamics in two-dimensional organic solids

“…The solid and dashed arrows represent the voltage-increasing and voltage-decreasing processes, respectively. The hysteresis appears only in the deuterated compound but not in the hydrogenated one (after [627]). D 3 (Cat-EDT-TTF) 2 .…”

“…Measuring the current density-electric field characteristics of κ-D 3 (Cat-EDT-TTF) 2 above and below the charge-ordering transition Ueda et al found a negative differential resistance and hysteresis, which is considered to be induced by the deuterium dynamics [627]. Applying a pulsed voltage, the initial charge-ordered state changes to a metastable state through a high-conducting (excited) state, which results in the appearance of the hysteresis, as illustrated in Figure 76(a).…”

Modulation of the electronic states and magnetic properties of nickel catecholdithiolene complex by oxidation-coupled deprotonation

“…8,[10][11][12][13][14][15][16][17][18] Recent studies have demonstrated that the electrostatic and dynamic properties of protons in H-bonds can directly modulate the electronic functionalities of molecular crystals in the solid state. [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] A clear strategy for controlling functionalities based on such electron-proton coupling is crucial to significantly expand a range of material designs for desired functionalities to pioneer novel physical properties and functionalities. However, it is still challenging to realize electron-proton coupling phenomena in the solid state.…”

“…Infrared spectroscopic observations revealed that this crystal displays a charge transfer (p-electronic state modulation) with proton transfer under high pressure. [36][37][38] catechol-fused tetrathiafulvalene [25][26][27][28][30][31][32][33]39,40 (Fig. 1, left) with a single-well (or low-barrier double-well for deuterated one) [OÁ Á ÁH(D)Á Á ÁO] (H: hydrogen; D: deuterium) H-bond, unique electronic functionalities coupled with proton or deuteron dynamics in the solid state have been realized, such as quantum spin liquid states associated with a quantum fluctuation of protons, 26,39 and switching of magnetism and electrical conductivity.…”

“…1, left) with a single-well (or low-barrier double-well for deuterated one) [OÁ Á ÁH(D)Á Á ÁO] (H: hydrogen; D: deuterium) H-bond, unique electronic functionalities coupled with proton or deuteron dynamics in the solid state have been realized, such as quantum spin liquid states associated with a quantum fluctuation of protons, 26,39 and switching of magnetism and electrical conductivity. [30][31][32][33] The key to realizing such electron-protoncoupled phenomena is the significant modulation of the electronic state with H-bond formation and/or proton transfer. As noted for the aforementioned materials, the introduction of hydroxy groups to p-conjugated molecules (e.g., catechol moiety) seems to be an effective molecular design based on the above-mentioned key points.…”