A memory device including a first conductive layer; a second conductive layer; a resistance change region provided between the first conductive layer and the second conductive layer; a first region provided between the resistance change region and the first conductive layer, the first region including a first element selected from the group consisting of niobium, vanadium, tantalum, and titanium, and a second element selected from the group consisting of oxygen, sulfur, selenium, and tellurium, the first region having a first atomic ratio of the first element to the second element; and a second region provided between the first region and the resistance change region, the second region including the first element and the second element, the second region having a second atomic ratio of the first element to the second element, the second atomic ratio being smaller than the first atomic ratio.

Discloses is an electronic device and a method for its operation. The device has first and second electrodes and an active material. The active material has selectable and stable first and second macroscopic quantum states, such as charge density wave ordered states, having respectively first and second values of electrical resistivity ρ.sub.1 and ρ.sub.2 at the same temperature. ρ.sub.1 is at least 2 times ρ.sub.2. The method includes the step of switching between the first and second macroscopic quantum states by injection of current via the electrodes.

A memory device of an embodiment includes: a first conductive layer; a second conductive layer; a resistance change region provided between the first conductive layer and the second conductive layer; a first region provided between the resistance change region and the first conductive layer, the first region including a first element selected from the group consisting of niobium, vanadium, tantalum, and titanium, and a second element selected from the group consisting of oxygen, sulfur, selenium, and tellurium, the first region having a first atomic ratio of the first element to the second element; and a second region provided between the first region and the resistance change region, the second region including the first element and the second element, the second region having a second atomic ratio of the first element to the second element, the second atomic ratio being smaller than the first atomic ratio.