A submatrix of semiconductor material contains plural electron conduction annels in either or both series and parallel arrangements. Electrons in the channels are confined by the submatrix and a surrounding main matrix provides photon confinement within the submatrix for nonequilibrium phonons which are mutually interchanged between channels. The confinement enhances the efficiency of energy and momentum transfer by means of nonequilibrium phonons. Embodiments of the invention as a transformer, bistable switch, controlled switch and amplifier are disclosed.

FIELD OF THE INVENTION 
This invention relates to solid state electronic devices, and more 
specifically relates to a novel control mechanism for controlling the 
electrical function of a solid state device by controlling interchannel 
exchange of nonequilibrium phonons. 
BACKGROUND OF THE INVENTION 
Phonon modulated switching devices are known, and are described in U.S. 
Pat. No. 5,374,831 entitled Quantum Well Phonon Modulator in the names of 
Mitra Dutta, et al., which is assigned to the assignee of the present 
invention and which is incorporated herein by reference. As disclosed in 
that patent, optical phonon emission from a first quantum well provides a 
scattering mechanism for electrons in an adjacent well, to reduce the 
current in the adjacent well. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a plurality of parallel spaced 
electron channels are embedded within a surrounding submatrix which at 
least partially is formed of semiconductor material. The submatrix, in 
turn, is surrounded by a matrix. Selected ones of the spaced channels may 
be formed of separate series-connected channels. The surrounding matrix 
provides phonon confinement to the submatrix for the various channels. An 
interchannel exchange of nonequilibrium phonons then provides a novel 
picosecond control mechanism of electrical functions due to electron and 
phonon quantization. 
Phonon confinement can be obtained in any desired manner so long as the 
various electron channels can mutually exchange phonons. The novel 
structure of the invention can be employed to produce such varied devices 
as amplifiers, switches, oscillators and current and voltage transformers. 
Such devices will be insensitive to electrical conditions such as 
parasitic inductance, resistance and capacitance which hinder the 
performance of conventional high speed devices. 
In general, the present invention provides a novel method to control 
electrical functions based on the confinement of phonons within a matrix 
containing electronic channels wherein the confinement enhances the 
efficiency of energy and momentum transfer by means of nonequilibrium 
phonons. 
Other features and advantages of the present invention will become apparent 
from the following description of the invention which refers to the 
accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 shows the principal structures of the novel interchannel 
nonequilibrium confined-phonon exchange device. Thus, the main structures 
are the volumes I and III which provide a surrounding matrix of material 
which provide phonon confinement within volume II. Volumes I and III may 
be any material, with different phonon frequencies from those in volume 
II. The dimensions of volumes I and III, concentration of charge carriers 
and the selected impurities in these volumes may vary depending on the 
application for which the invention will be used. However, depending on 
the application, those skilled in the art would know what physical 
parameters to select given the present specification. 
Volumes I and III may also be simply free space for a free standing 
structure. 
Volume II shows the volume or submatrix in which electron channels are 
embedded, surrounded by matrix I. Similar to Volume II, submatrix II of 
FIGS. 1 and 2 may be any semiconductor material which is different from 
the materials of volumes I and III. With respect to the dimensions of 
submatrix II, at least one dimension of the cross-section of this 
submatrix should not exceed several hundred nanometers. 
In both of the embodiments of FIGS. 1 and 2, phonons are confined within 
submatrix II to enhance interchannel coupling between electron channels 
within submatrix II to be described. 
FIG. 3 shows submatrix II in perspective view, and shows two electron 
channels 20 and 21 extending through the submatrix. Channels 20 and 21 may 
be any semiconductor material with phonon frequencies similar to those in 
surrounding submatrix II, but with a different forbidden energy bond gap 
than selected for submatrix II. The lengths of channels 20 and 21 may be 
any dimension, depending on the application. However, at least one 
dimension of the cross sections of channels 20 and 21 should not exceed 
100 nanometers and the spacing between channels 20 and 21 should be in the 
range of approximately 1 to 20 nanometers. As those skilled in the art 
will appreciate, it will be desirable to have an impurity and/or defect 
concentration as low as possible in these channels 20 and 21. While 
channels 20 and 21 are shown as square in cross-section, any desired 
cross-sectional shape can used. 
Each of channels 20 and 21 receive contact metallizing at their opposite 
ends, at the exterior of volume II (or I) shown as metal contacts 20a and 
21a respectively in FIG. 3. Identical contacts will be placed on the 
opposite ends of channels 20 and 21, which are not seen in FIG. 3. In 
operation, nonequilibrium phonons exchanged between channels 20 and 21 
will modulate the electron current in the other channel. 
FIG. 4 shows another geometry for parallel channels 23 to 27. As will be 
described in connection with FIGS. 7 and 7a, the structure of FIG. 4 can 
be used to define a transformer. Contacts 23a to 27a are formed by 
metallizing the ends of channels 23 to 27a respectively as shown. Similar 
contacts will be applied to the opposite ends of channels 23 to 27, not 
seen in FIG. 4. 
While FIGS. 3 and 4 show parallel electron channels, it is also possible to 
arrange the electron channels serially, as shown in FIG. 5. Thus, two 
channels 30 and 31 may be connected in series within the submatrix II. 
Channel 30 has a contact 31a at its one end and is connected to channel 31 
at its other end. Channel 31 is metallized at its opposite end, not seen. 
Channels 30 and 31 may be formed by one of three ways. First, the channels 
30 and 31 may be formed by two different materials with different energy 
band gaps but similar optical phonon frequencies. Second, channels 30 and 
31 may be formed from the same material, but the channels are separated by 
a spacer which is transparent to phonons and which is opaque to charge 
carriers. Third, channels 30 and 31 may also be formed from one 
homogeneous channel (as opposed to two separate channels) wherein the 
charge carrier separation is accomplished by means of applying an 
electrostatic potential to a central electrical contact(s) attached to 
one, two, three or all four side walls of the homogeneous channel. 
As shown in FIG. 6, series-arranged channels 30 and 31 can be arranged in 
parallel with other channels, shown as series channels 40, 41 and 42. 
Contact 40a is also shown in FIG. 6. 
Channels 40, 41, 42 have the same structure as channels 30 and 31 of FIGS. 
5 and 6; the only difference is that there are three channels connected in 
series instead of two channels. The number of channels in series will, as 
those skilled in the art will recognize, depend on the application of the 
structure. The spacing of the channels in series will range from one 
atomic layer to approximately 20 nanometers. 
FIG. 7 shows the manner in which the structure of FIG. 4 can be arranged to 
form a transformer. FIG. 7a is an equivalent circuit of the transformer. 
In FIG. 7, electron channel 23 is connected to terminals A and A' at its 
opposite respective ends. The channels 24 to 27 (any desired number can be 
used) are connected in a series coil form by external wiring connected to 
the terminals B and B'. The external winding can be formed by conductive 
traces on the exterior semiconductor body. 
The structure of FIGS. 7 and 7a operates as follows: 
An input voltage .sub.AA is applied to contacts AA'. This induces an output 
voltage V.sub.BB at terminals BB', which is related to V.sub.AA by the 
relationship: V.sub.BB =.UPSILON.NV.sub.AA, where .UPSILON. is the 
efficiency of Interchannel Phonon Coupling and N is the number of electron 
channels in the output circuit. Due to effective phonon coupling in the 
structure and assuming N&gt;1, V.sub.BB &gt;V.sub.AA, i.e., the device serves as 
a step-up voltage transformer. The interchange of input and output 
connections makes it possible to get greater current in the AA' circuit 
than that applied to BB' circuit, so that the device can also serve as a 
step-up current transformer. In contrast to transformers operating by 
magnetic field flux, the transformer of FIG. 7 operates not only in AC but 
also in DC regimes. 
FIG. 8 shows the manner in which the device of the invention can be 
arranged to define a bistable logic element. Thus, the structure of FIG. 5 
can be employed with the contacts 30a and 31a connected to terminal 
electrodes 30b and 31b, respectively. A control terminal 50 is connected 
to the connection region 51 between conduction channels 30 and 31. 
FIG. 8a shows the potential distribution in the coupled channels 30 and 31 
for a symmetric load. As shown, the voltages V.sub.1 and V.sub.2 can be 
switched from high to low and from low to high by varying the control 
voltage V.sub.B. 
FIGS. 8b and 8c show the bistable current-voltage characteristics for the 
device of FIG. 8, as the control voltage V.sub.B varies. Thus currents 
I.sub.30 and I.sub.31 through channels 30 and 31 respectively switch as 
shown. 
The structure of FIG. 8 can be modified by adding a parallel channel 60 
having metallized contacts 60a and 60b at its opposite ends as shown in 
FIG. 9. Terminals 60c and 60d are connected to contacts 60a and 60b 
respectively. The added coupled channel 60 enables the device of FIG. 9 to 
operate as a controlled switch between terminals 60c and 60d. 
In operation, the voltage applied to terminals 60c and 60d controls the 
current in channel 60 and thus the generated flux of nonequilibrium 
phonons. If this voltage is non-zero, then the phonon system in the 
structure becomes asymmetric and leads to the switching of the device to 
one of the bistable branches. Depending on the direction of current in 
channel 60, either channel 30 or channel 31 can be closed, i.e., switched 
into a low-current regime. 
FIG. 10 shows a channel arrangement in submatrix II which creates an 
amplifier device. Thus, a first channel 70 is provided which contains a 
potential barrier 71. Channel 70 has end contacts and terminals 72 and 73. 
A parallel channel 75 has terminals 76 and 79. 
The structure of FIG. 10 is similar to that of FIG. 9. The only difference 
is that channel 70 contains a potential barrier 71 for charge carriers. 
This potential barrier 71 can be created either by an electrostatic 
potential applied to the central contact 50 as in FIG. 9 or by a spacer of 
semiconductor material with a different energy band gap than and similar 
optical phonon frequencies as in the material of channel 70. The length of 
this spacer should range from approximately 10 to 100 nanometers. 
It should be noted that the structure of FIG. 10 could be carried out as on 
in series structure, as shown in FIG. 11. 
FIG. 12 shows the potential distributions V.sub.70 and V.sub.75 along 
channels 70 and 75, respectively in FIGS. 10 and 11. 
Note the built-in barrier existing in voltage V.sub.70 due to the barrier 
71. FIG. 13 shows the I-V characteristic for the device, and shows its 
operation as an amplifier. 
The device operation is as follows: 
Channel 70 contains a finite potential barrier (shaded area 71) for 
electrons moving along the channel 70. AC current applied to channel 75 
generates a time-modulated nonequilibrium phonon population. 
Nonequilibrium phonons provide modulation of the electron gas temperature 
in channel 70. This results in current modulation in channel 70. Due to 
presence of the potential barrier in channel 70, the modulation depth of 
current I.sub.1 in this channel exceeds modulation depth of current 
I.sub.75 in channel 2. Thus, the device of either FIGS. 10 or 11 serves as 
AC current amplifier. That is, a small change .DELTA.I.sub.75 in current 
I.sub.75 will produce a large change .DELTA.I.sub.70 in current I.sub.70. 
Although the present invention has been described in relation to particular 
embodiments thereof, many other variations and modifications and other 
uses will become apparent to those skilled in the art. It is preferred, 
therefore, that the present invention be limited not by the specific 
disclosure herein, but only by the appended claims.